Answer:
D = -9
Step-by-step explanation:
Solve for D:
D/3 + 10 = 7
Hint: | Put the fractions in D/3 + 10 over a common denominator.
Put each term in D/3 + 10 over the common denominator 3: D/3 + 10 = D/3 + 30/3:
D/3 + 30/3 = 7
Hint: | Combine D/3 + 30/3 into a single fraction.
D/3 + 30/3 = (D + 30)/3:
(D + 30)/3 = 7
Hint: | Multiply both sides by a constant to simplify the equation.
Multiply both sides of (D + 30)/3 = 7 by 3:
(3 (D + 30))/3 = 3×7
Hint: | Cancel common terms in the numerator and denominator of (3 (D + 30))/3.
(3 (D + 30))/3 = 3/3×(D + 30) = D + 30:
D + 30 = 3×7
Hint: | Multiply 3 and 7 together.
3×7 = 21:
D + 30 = 21
Hint: | Isolate terms with D to the left hand side.
Subtract 30 from both sides:
D + (30 - 30) = 21 - 30
Hint: | Look for the difference of two identical terms.
30 - 30 = 0:
D = 21 - 30
Hint: | Evaluate 21 - 30.
21 - 30 = -9:
Answer: D = -9
