Question

8x+2y=5 2x+5y=7 solve by elimination method

Answer 1

Answer: $8x+2y=5 =====(i)\\2x+5y=7=====(ii)\\\\4(ii)=4(2x+5y)=28\\\\8x+20y=28 =====(iii)\\\\(iii)-(i)=8x+20y-8x-2y=28-5\\\\18y=23\\\\y=\frac{23}{18}$

Step-by-step explanation:

$8x+2y=5 =====(i)\\2x+5y=7=====(ii)\\\\4(ii)=4(2x+5y)=28\\\\8x+20y=28 =====(iii)\\\\(iii)-(i)=8x+20y-8x-2y=28-5\\\\18y=23\\\\y=\frac{23}{18}$

now we can eaisly take out the values of x by putting the value of y in eq. (i) or (ii)

$x=\frac{11}{20}$