Question

Determine, without the use of a calculator, the value of x² +3x²+x. if

x=-2. Show all your steps.
QUESTION 4
a)
A scuba diver descends from the surface at a rate of 10 m per minute.
1) How long will it take the diver to get to a depth of 25 m?
2) How deep will the diver be after 3 minutes?

3) How deep will the diver be after x minutes?

Answer 1

x^2 + 3x^2 + x = 0
x = -2

Working:

x^2 + 3x^2 + x = 0
4x^2 + x = 0
x(4x+1) = 0
x(4x+1) = x(0) {*x gets cancelled*}

So,
4x+1=0
4x=-1
x=-1/4

Therefore, the answer to x^2 + 3x^2 + x Is not x=-2

QUESTION 4

(a) speed of scuba diver = 10 m/min

1) Distance (d) = 25 m
Speed (s) = 10 m/min
Time (t) = ?

Speed = Distance / Time
Time = Distance / Speed

t = d/s
= 25 m / 10 min
= 2.5 m/min

2) Time (t) = 3 min
Speed (s) = 10 m/min
Distance (d) = ?

s = d/t
d = s x t

d = s x t
= 10 m/min x 3 min
= 30 m

3) Question not clear.