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6 votes
Solve these 2 Question. 50 Points + Brainelist​

Solve these 2 Question. 50 Points + Brainelist​-example-1
User Raccoon
by
4.5k points

2 Answers

11 votes

Answer:

(a) x=50 y=30

Step-by-step explanation for (a):

First use system of equations. Isolate a variable and substitute.

2x + 3y = 190

3x + y = 180

Isolate

subtract 3x from both sides of the second equation

y = 180 - 3x

since 180 - 3x = y, you can substitute this into the first equation for y

Substitute

2x + 3y = 190

2x + 3(180 - 3x) = 190

Distribute the 3

2x + (540 - 9x) = 190

Solve for x

subtract 540 from both sides

2x - 9x = -350

simplify

-7x = -350

divide each side by -7

x = 50

But you still need to solve for y, so substitute the x back into the first equation.(But really you could use either equation)

2(50) + 3y = 190

subtract 100 (2 * 50) from both sides

3y = 90

y = 30

Check your work by resubstituting.

3(50) + 30 = 180.

(b) This one is weird.

(x + 2)^3 expands to (x + 2)(x + 2)(x + 2).

(Remember, it is NOT (x^3 + 8), you don't "distribute" the exponent)

It then simplifies to x^3 + 6x^2 + 12x + 8, and x = 5 is NOT an answer here. Maybe there is something more that you might not have screenshotted?

*edit its not asking to prove x is a solution(which i thought lolllll) its asking to plug x = 5 into the equation*

User Carmelita
by
3.8k points
8 votes

using simultaneous equation:

2x + 3y = 190

3x + y = 180 * 3

Then:

2x + 3y = 190

9x + 3y = 540

--------------------

-7x = -350

x = 50

Insert this in equation 1 to find value of y:

2x + 3y = 190

2(50) + 3y = 190

3y = 190 - 100

3y = 90

y = 30

expanding the following:

→ (x + 2)³


\sf apply \ cubic \ formula : \bold{\left(a+b\right)^3=a^3+3a^2b+3ab^2+b^3}


\rightarrow \sf x^3+3x^2\cdot \:2+3x\cdot \:2^2+2^3


\rightarrow \sf x^3+6x^2+12x+8

Justify for x = 5


\rightarrow \sf (5)^3+6(5)^2+12(5)+8


\rightarrow \sf 125+150+60+8


\rightarrow \sf 343

User Vineet Shah
by
4.4k points