Combine like terms.
8x2 + 2(x2 − 1) =

Step-by-step explanation:

8x² + 2(x²-1) = 8x² + 2*x²  - 2*1

= 8x² + 2x² -2

= 10x² -2

Like terms: 8x² , 2x²

x = 10.1

step-by-step explanation:

all of the angles of a tirangle add up to 180º

180 - 65 = 115 (since we already know the value of one angle)

(2x + 7) + (8x + 7) = 115

(combins like terms) 10x + 14 = 115

(isolate the variable subtract 14 from both sides): 10x = 101

(find the variable divide both sides by 10): x = 101/10

x = 10.1