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*