Question

a + 2d = 600
a + 6d = 700
find d and a
​step by step

Answer 1

Answer:

a=550 d=25

Step-by-step explanation:

subtract the equations

a+6d=700. eq.1

-a-2d=600. eq.2

4d=100

d=25

substitute the value in eq.2

a+2(25)=600

a =600-50

a=550

Answer 2

Step-by-step explanation:

a+2d=600

a=600-2d -----(1)

put the value of a in

a+6d=700

600-2d+6d=700

4d=700-600

4d=100

d=100/4

d=25

NOW put the value of d in equation (1)

a=600-2d

a=600-2×25

a=600-50

a=550

hence, a=550 and d= 25