Answer:
Step-by-step explanation:
We can simplify (cross multiply) to get 
Then we easily simplify to get 
Answer:
a = 3
Step-by-step explanation:
Since x = 7 is a solution, substitute x = 7 into the equation and solve for a
4(7) - 2(7 + a) = 8 , that is
28 - 2(7 + a) = 8 ( subtract 28 from both sides )
- 2(7 + a) = - 20 ( divide both sides by - 2 )
7 + a = 10 ( subtract 7 from both sides )
a = 3
Answer:
120 trees
Step-by-step explanation:
4x10=40
40x3=120
120 trees will be planted
Answer:
x = 8
Step-by-step explanation:
2(78°) = 20x - 4
156 = 20x - 4
add 4 to each side of the equation:
160 = 20x
divide both sides by 20:
x = 8