Question

What is the value of a in the equation 5a – 10b = 45, when b = 3?

Answer 1

So Since we know what b equals. We can just plug it into the equation
b = 3
5a -10(3) = 45

First step is to solve -10(3) that means we multiply these two numbers.
-10 x 3 = -30
Now plug that in for what it was in the equation.

5a - 30 = 45

Now the next step is to add 30 to both sides to cancel out -30

5a - 30 = 45
+30 = +30
*************** Now the 30's on the left side disappear and we solve on the right side.
45 + 30 = 75

Now set up your equation once again.

5a = 75

Now we divide both sides by 5 to isolate (or get a to be alone)
5a = 75
÷5 = ÷5
********* the 5's on the left side disappear and we solve on the right side.

75 ÷ 5 = 15

So here's what we have left.
a = 15

Good Luck! :)

Answer 2

Here you go. Do you think that you could help me with my question

5a – 10b = 45
5a – 10(3) = 45
5a – 30 = 45
+30 +30
5a = 75/5
a = 15