Algebra: Substitution Practice 1 Substitution is very easy if you follow the three key steps carefully, and doing so can help you achieve 100% accuracy. To strengthen your understanding, here are 5 practice questions for you to try. Related Lessons: S1 Algebra Substitution Practice 1 - Question 1 Given the formula \(C=2\left(x-y\right)\), find the value of \(x\) when \(y=12\) and \(C=4\). Practice 1 - Question 2 Given that \(x=3\left(y-2z\right)\), find the value of \(z\) when \(x=21\) and \(y=42\). Practice 1 - Question 3 Given that \(y+\frac{3a}{b}=3x+\frac{14c}{5}\), find the value of c given that \(y=4\), \(a=2\), \(b=-3\) and \(x=-4\). Practice 1 - Question 4 Given that \(c=-5\), \(d=3\) and \(e=2\), find the value of \(c-2d+5e\). Practice 1 - Question 5 Given that \(a=-2\), \(b=3\) and \(c=5\), evaluate \(\left(a-b\right)^2\times\left(c+ab\right)^3\). Share With Friends: Related Lessons: S1 Algebra Substitution