Solve: \(\frac{1}{2}x-3=5\) and check that your answer is reasonable.
- \(x=6\)
- \(x=10\)
- \(x=16\)
- \(x=24\)
Students will build Grade 7 mastery of solving multi-step problems with rational numbers using models, equations, and test-style reasoning.
Solve: \(\frac{1}{2}x-3=5\) and check that your answer is reasonable.
Solve \(3x+7=22\) and explain why your answer is reasonable.
Solve for \(y\): \(2y-8=-14\) and check your answer makes sense.
Which value of \(x\) satisfies \(\frac{x}{4}+2=5\)? Use mental math to verify.
Solve: \(5(x-2)=30\) and verify using inverse operations.
A savings account has a balance of \(-$15\) (overdraft). After depositing $50, what is the new balance? Write and solve an equation.
Marcus earns $12 per hour. After working 8 hours, he spent $15 on lunch. How much money does he have left?
What is the solution to \(\frac{3}{4}x=12\)? Use a reciprocal to solve and verify.
Add \(3\) to both sides: \(\frac{1}{2}x=8\). Multiply by \(2\): \(x=16\). Check: \(\frac{1}{2}(16)-3 = 8-3 = 5\) ✓. Reasonableness: Half of 16 is 8; minus 3 gives 5. ✓
Subtract \(7\): \(3x=15\). Divide by \(3\): \(x=5\). Check: \(3(5)+7 = 15+7 = 22\) ✓. Reasonable: three times 5 is 15; add 7 gives 22.
Add \(8\): \(2y=-6\). Divide by \(2\): \(y=-3\). Check: \(2(-3)-8 = -6-8 = -14\) ✓. Reasonable: negative answer expected (result is negative).
Subtract \(2\): \(\frac{x}{4}=3\). Multiply by \(4\): \(x=12\). Mental math check: \(\frac{12}{4}+2 = 3+2 = 5\) ✓. Reasonable: one-quarter of 12 is 3; add 2 gives 5.
Divide by \(5\): \(x-2=6\). Add \(2\): \(x=8\). Check: \(5(8-2) = 5(6) = 30\) ✓. Reasonable: five groups of 6 equals 30.
Equation: \(-15 + d = b\) where \(d = 50\) (deposit). Or: \(-15 + 50 = 35\). Check: Starting with \(-$15\) debt, adding \($50\) leaves \($35\) surplus. Reasonable.
Earnings: \(12 \times 8 = 96\). After spending: \(96 - 15 = 81\).
Multiply both sides by \(\frac{4}{3}\) (reciprocal): \(x = 12 \times \frac{4}{3} = 16\). Check: \(\frac{3}{4}(16) = \frac{3 \times 16}{4} = \frac{48}{4} = 12\) ✓. Reasonable: three-quarters of 16 is 12.