They give us the length of side of the square which is 3-7x.
To get an expression for the perimeter that is expressed as a product we have to multiply the expression 3-7x by four since every square has four sides. This will give us an expression of 4(3-7x). We than can use the distributive property to multiply everything inside the parenthesis by 4. This will give us an expression of 12-28x.
19-25=-6 that is your answer
The answer is x².
f(x) = <span>5x - 6
</span>g(x) = x²<span> - 5x + 6
(f + g)(x) = f(x) + g(x)
= </span>5x - 6 + x² - 5x + 6
= x² + 5x - 5x + 6 - 6
= x² + 0 + 0
= x²
Couldn't it be 54, 53 52, or 51