Step-by-step explanation:
2(3(7)-1)
= 2(21-1)
=2(20)
=40
Answer:

Step-by-step explanation:
Add up all the sides to get the perimeter:

Answer:
2/7.
Step--step explanation:
1/2 * 4/7.
Multiply the numerators and the denominators:
= 1*4 / 2*7
= 4 / 14 Now divide numerator and denominator by 2:
= 2/7.
for the first one set 3y+y=180 and y+x=180
the second one set w+y=180, 42+x=180, y+20=180, and 87+v
Answer:
16
Step-by-step explanation: