I believe the answer is A.
Absolute value best proves my answer.
Absolute value is how far a number is from zero.
Use pythagorean theorem for all of them
a. 3, 4, 5
3^2+4^2?5^2
9+16?25
25=25
right
b. 5, 6, 7
5^2+6^2=7^2
25+36=49
61>49
acute
c. 64+81=144
145>144
acute
hope this helps!
10(0.5x + 6) = 8
5x + 60 = 8
5x = 8 - 60
5x = -52
x = -52/5
x = -10.4
Combine the like terms
-x-x^2+7
Root root 20^2 - 4^2
X = 2
