Solve for x:
1.
4x - 7 = 3
Add 7 to both sides
4x = 10
Divide both sides by 4
x = 10/4
Simplify:
x = 5/2
Answer for question 1: x = 5/2
2.
13 + 2x/3 = 15
Multiply both sides by 3
39 + 2x = 45
Subtract 39 from both sides
2x = 6
Divide both sides by 2
x = 3
Answer for question 2: x = 3
3.
10x + 7 = 15
Subtract 7 from both sides
10x = 8
Divide both sides by 10
x = 8/10
Simplify
x = 4/5
Answer for question 3: x = 4/5
Answer:48.6
we know that
You can paint 75 square feet of a surface every 45 minutes
so
using proportion
Find out how long it takes you to paint a surface area of 81 square feet
45(81)/75=48.6
hope this helped and I hope you get a correct answer :D
Answer: 
Step-by-step explanation:
We can rewrite the left hand side as a perfect square, more specifically
So, taking the square root of both sides,
20 beacause 20 x 2 = 40 and twice as many means 2 x ....
