Answer:
x=26
Step-by-step explanation:
∠REA and ∠REB are on the straight line AB. Since they are on a straight line together, they are supplementary and must add to 180 degrees.
∠REA+∠REB=180
We know that ∠REA is 5x+7 and ∠REB is 43 degrees.
∠REA=5x+7
∠REB=43
5x+7+43=180
Combine like terms by adding 7 and 43.
5x+(7+43)=180
5x+50=180
Now we need to solve for x. Perform the inverse operation to both sides.
50 is being added to 5x. The inverse of addition is subtraction; subtract 50 from both sides.
5x+50-50=180-50
5x=180-50
5x=130
x is being multiplied by 5. The inverse of multiplication is division ; divide both sides by 5.
5x/5=130/5
x=130/5
x=26