The angles need to be congruent for the two triangles to be similar.
Hope this helps :)
Step-by-step explanation:
1st
8x-59 + 2x-11 = 180
10x -70 = 180
10x = 180 + 70
10x = 250
x = 25
2nd
8x - 59 = 15y + 6
8(25) -59 = 15y + 6
200 -59 = 15y + 6
141 = 15y + 6
15y + 6 = 141
15y = 141 - 6
15y = 135
y = 135/15
y = 9
First, let's put all of the variables together.
4m + 5m + 5 + 40 = 180.
Add them.
M is the same multiplier, so we can add 4 and 5 together to make 9m.
Add 5 and 40.
9m + 45 = 180.
From here, we can go two ways. I will show the first way, which is my personal preference.
We want to get rid of the coefficient on m to isolate it, so we must divide it by its coefficient. The coefficient on m is 9. So, divide m by 9. We must also divide everything else by 9.
9m/9 = 1m
45/9 = 5
180/9 = 20
Plug it in--
m + 5 = 20.
Subtract the 5 from both sides to isolate m.
m = 15.
Answer:
16 minutes
Step-by-step explanation:
80% of 20 is
80/100 * 20 = 16
