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1. y = (x - 5)(x + 1), Find y if x = - 3.

2. v= u + at
(a)
YEAR 7 HOME WORK
Work out v when u = 23, a = 4, and t = 3
(b)
Work out u when v= 30, a = 2 and t = 8
(c) Work out t when v = 40, u = 12 and a = 4
3. The circumference of a circle can be found using the formula C = 2nr or C = nd
Find the circumference of a circle with radius 8 cm.
Leave your answer to one decimal place.

4. Speed is calculated using the formula S=
Find the speed at which a car travelled if it took 2 hours to travel a distance of 100 km
D
T
where D is distance and T is time.

User Matt Rix
by
8.3k points

2 Answers

4 votes

Answer:

1) y=-2, y=-8

2a) v=35

b) u=12

c) t=7

3) c=50.3

4) s=50

User DylanYoung
by
8.1k points
4 votes

1 ]

Given:-


  • \tt{y = ( x - 5 ) ( x + 1 ) }


\:


  • \tt{x = - 3}


\:

To find:-


  • \tt \: y = ?


\:

Solution:-


  • \tt{y = ( x - 5 ) ( x + 1 )}


\:

now , put the value of x = -3 in equation


  • \tt \: y = ( -3 - 5 ) ( -3 + 1 )


\:


  • \tt \: y = ( - 8 ) ( - 2 )


\:

or


  • \tt \: y = 16


\:


\texttt{The value of \boxed{ \tt \red{ y = ( -8 ) ( -2 )} } \: or \boxed{ \tt \red{ 16}} !}


\:

━━━━━━━━━━━━━━━━━━━━━━━━━━━━

2 ]


\texttt{v = u + at} \: - - - \texttt{given \: formula \: or \: eqn}

a ) ----»

Given:-


  • \tt \: u = 23


\:


  • \tt \: a = 4


\:


  • \tt \: t = 3


\:

To find:-


  • \tt \: v = ?


\:

Solution:-


  • \tt \: v = u + at


\:

now , put the given value in equation


  • \tt \: v = 23 + 4×3


\:


  • \tt \: v = 23 + 12


\:


  • \boxed{\tt \purple{ v = 35}}


\:

____________________________________

b )

Given:-


  • \tt \: v = 30


\:


  • \tt \: a = 2


\:


  • \tt \: t = 8


\:

To find:-


  • \tt \: u = ?


\:

Solution:-


  • \tt \: v = u + at


\:

put the given value in equation


  • \tt \: 30 = u + 2×8


\:


  • \tt \: 30 = u + 16


\:


  • \tt \: 30 - 16 = u


\:


  • \tt \: 14 = u


\:


  • \boxed{ \tt \pink{ u = 14}}


\:

____________________________________

c )

Given:-


  • \tt \: v = 40


\:


  • \tt \: u = 12


\:


  • \tt \: a = 4


\:

To find:-


  • \tt \: t = ?


\:

Solution:-


  • \tt \: v = u + at


\:

now , put the given value in equation


  • \tt \: 40 = 12 + 4t


\:


  • \tt \: 40 - 12 = 4t


\:


  • \tt \: 28 = 4t


\:


  • \tt \cancel (28)/(4) = t


\:


  • \tt \: 7 = t


\:


  • \boxed{\texttt{ \green{t = 7}}}


\:

━━━━━━━━━━━━━━━━━━━━━━━━━━━

3 ]

Given:-


  • \tt \: radius = 8


\:

To find:-


  • \texttt{circumference of circle = ?}


\:

By using given formula:-


  • \underline{ \tt \: \: C = 2πr \: \: }


\:

Solution:-


  • \tt \: C = 2πr


\:


  • \texttt{C = 2× 3.14× 8 [ as we know that the value of π = 3.14 constant ]}


\:


  • \tt{C = 16 × 3.14}


\:


  • \tt{C = 50.24}


\:


\texttt{The Circumference of the circle is { \blue{50.24}} !}


\:

━━━━━━━━━━━━━━━━━━━━━━━━━━━

4 ]

Given:-


  • \texttt{Time ( T ) = 2h}


\:


  • \texttt{Distance ( D ) = 100km}


\:

To find:-


  • \texttt{Speed ( S ) = ?}


\:

By using formula:-


  • \underline{\tt{ \: \: Speed= (Distance)/(Time) \: \: }}


\:

Solution:-


  • \tt \: S = (D)/(T)


\:


  • \tt \: S = \cancel(100)/(2)


\:


  • \tt \: S = 50


\:


\texttt{The Speed of the car is \color{green}50.}

━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

hope it helps⸙

User Vikrant Chaudhary
by
7.8k points

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