You need his sisters age to solve the problem. if y is the sisters age and x is Johns age, then the equation is
3y-2=x
Hope this helps! Don't flip the sign at the end when you divide because it's a positive number being divided. Only flip when it's a negative number. Any questions comment!
Use the substitution method for x
y= 4(-2)-1
y= -8-1
y= -9
Answer is y=-9
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Answer:
Is this pure maths cause I don't know what's going on here