Answer:
the first one because supplementary means angles which add up to 180 and 180 degrees is a straight line and the third one because they both share the same vertex and side
Step-by-step explanation:
Answer:
x=3
y=3
Step-by-step explanation:
x = 6-y
-plug in (6-y) into first equation
2(6-y)+3y = 15
12-2y+3y=15
-2y+3y = 3
y=3
x=6-3
x=3
double check:
(2*3) + (3*3) = 6 + 9 = 15
3 + 3 = 6
Step-by-step explanation:
x2^+8x=-20
9x^2=20
x^2=20-9
x^2=11
√x^2=√11
x=√11