(a) 95 = (x+7)*(x-7)
(b) 95 = (x+7)*(x-7)
Expand the brackets:
95 = x² -7x + 7x -49 = x² - 49
Subtract x² from both sides:
95-x² = -49
Subtract 95 from both sides:
-x²=-49-95
-x²= -144
Divide both sides by -1 to get rid of the negative numbers:
-x²/-1=-144/-1
x²=144
Take the square root of 144:
x = ± squareroot of 144
x = 12 or -12
x = 12 because you cannot have a negative age so Trina is 12 years old.
Answer: 
Step-by-step explanation:






for 2 points A(xa;ya) and B(xb;yb)
the slope is (yb - ya) / (xb - xa)
here
the slope = 4 = (17-r) / (4-(-1))
(17-r) / 5 = 4
17 - r = 20
r = 17 - 20
r = - 3
point (-1 ; -3)
Your answer is (z+1+w) (z+1-w)
Your total will be $60, you will have saved $15