Math reasoning exercise set 4

Question 1:

We need to frame equations and solve. The equations are ….A+B =-1   A+C= -2    B+C=-7

To solve these equations.. you can either use algebra. or substitute suitable numbers

Lets add these equations    A+B =-1   A+C= -2   

A+B+A+C = -2-1

2A+B+C = -3.. Replace B+C with -7

2A + (-7) = -3

2A = +7-3 

2A = 4…. A =2

Substitute value of A in other equations

2+B =-1    B = -1-2 = -3

2+C= -2   C =-4

Hence A =2, B=-3 and C=-4

Follow the same steps to solve question 2 and 3

Question 2 – A=1, B=4  C= 4

Question 3 – A=9  B =-21  C = 9