Texas Essential Knowledge and Skills (TEKS)

Grade: 
7th Grade 
Standard: 
7.10.A 
Description: 
write onevariable, twostep equations and inequalities to represent constraints or conditions within problems; 
Standard: 
7.10.B 
Description: 
represent solutions for onevariable, twostep equations and inequalities on number lines; and 
Standard: 
7.10.C 
Description: 
write a corresponding realworld problem given a onevariable, twostep equation or inequality. 
Standard: 
7.11.A 
Description: 
model and solve onevariable, twostep equations and inequalities; 
Standard: 
7.11.B 
Description: 
determine if the given value(s) make(s) onevariable, twostep equations and inequalities true; and 

7th Grade Math  Represent & Solve Equations Lesson
To solve an equation for an unknown value, keep the equation balanced while isolating the unknown.
First, divide both sides of the equation by 6. Then, subtract 4.2 from both sides of the equation.
6(x + 4.2)  =  36  6(x + 4.2) ÷ 6  =  36 ÷ 6  x + 4.2  =  6  x + 4.2 − 4.2  =  6 − 4.2  x  =  1.8 
First, add 10 to both sides of the equation. Then, divide both sides of the equation by 5.
5x − 10  =  15  5x − 10 + 10  =  15 + 10  5x  =  5  5x ÷ 5  =  5 ÷ 5  x  =  1 
First, subtract 0.7 from both sides of the equation. Then, divide both sides of the equation by 2.1.
2.1x + 0.7  =  7  2.1x + 0.7 − 0.7  =  7 − 0.7  2.1x  =  6.3  2.1x ÷ 2.1  =  6.3 ÷ 2.1  x  =  3 
