Please excuse my sloppy writing but the answer is 30
Answer:
b answer
Step-by-step explanation:
Answer:
x= 2 and y = -4
Step-by-step explanation:
8x + 3y = 4 ---------------------------------(1)
-7x + 5y = -34 -----------------------------(2)
Multiply through equation (1) by 5 and multiply through equation(2) by 3
40x + 15y = 20 ----------------------------(3)
-21x + 15y =-102----------------------------(4)
Subtract equation (4) from equation (3)
61x = 122
Divide both-side of the equation by 61
61x/61 = 122/61
(At the left-hand side of the equation 61 will cancel-out 61 leaving us with just x, while at the left-hand side of the equation 122 will be divided by 61)
x = 122/61
x=2
Substitute x= 2 into equation (1)
8x + 3y = 4
8(2) + 3y = 4
16 + 3y = 4
Subtract 16 from both-side of the equation
16-16 + 3y = 4-16
3y = -12
Divide both-side of the equation by 3
3y/3 = -12/3
y = -4
x= 2 and y = -4
I don't know if my answer is completely correct, but I think it's 100. All triangles add up to 180, and an isosceles triangle has 2 equal sides. 40 would be the 2 sides, and 180 subtracted from 80 equals 100.
