Question

solve 7s +3t=5 and
-8s+20t=6
​

Answer 1

multiplying 1st equation with 8and

Step-by-step explanation:

multiplying 2nd equation with 7 we get

56s+24t=40

-56s+140t=42

by solving we get

t=1/2 and s=1/2

Answer 2

Answer:

7s+3t=5 -------(i)

-8s+20t=6 ------(ii)

(i)×8 56s+24t=40 --------(iii)

(ii)×7 -56s+140t=42 -------(iv)

(iv)+(iii) 164t=82

t=1/2

now,put the value of t=1/2,to the equation of (i) {you may also choose another (ii) equation.}

let see,7s+3×1/2=5

=> 7s=5-3/2

=> 14s=10-3

=> 14s=7

=> s=1/2

ans, s=1/2,t=1/2