Hey there!
4x + 7 + 35 = 90°
4x + 42 = 90°
SUBTRACT 42 to BOTH SIDES
4x + 42 - 42 = 90 - 42
CANCEL out: 42 - 42 because it give you 0.
KEEP: 90 - 42 because it help solve for the x-value.
NEW EQUATION: 4x = 90 - 42
SIMPLIFY IT!
4x = 48°
DIVIDE 4 to BOTH SIDES
4x/4 = 48/4
CANCEL out: 4/4 because it give you 1
KEEP: 48/4 because it give you the x-value
NEW EQUATION: x = 48/4
SIMPLIFY IT!
x = 12
Therefore, your answer is: x = 12
Good luck on your assignment & enjoy your day!
~Amphitrite1040:)