I think a partial variation
Answer is c.
t = 0.5(d+h)
multiply both sides by 2 to cancel out the 0.5.
2t = d+h
2t - d = h
True because a triangle must have 3 angles that add up to 180 degrees and, since a right angle is 90 degrees, it cannot have 2 right angles
Answer: 25x² - 64
<u>Step-by-step explanation:</u>
(5x + 8)(5x - 8)
= 5x(5x - 8) + 8(5x - 8)
= 25x² - 40x + 40x - 64
= 25x² + 0x - 64
= ![\large\boxed{25x^2-64}](https://tex.z-dn.net/?f=%5Clarge%5Cboxed%7B25x%5E2-64%7D)
NOTE: descending powers means the biggest exponent goes first, then the next biggest exponent, etc.
For example: x⁴ then x³ then x² then x then the number (which is actually x⁰)