Question

how to solve this question in substitution method
5x+3y=21;2x-y=4

Answer 1

s first you have to know what is substitution method substitution method is a method where we get the value of x from any first or second equation and put in the first or second equation.
therefore...
2x-y=4.
2x=4+y
x=4+y/2.
now put this value in equation (I)
5x+3y=21
5*(4+y/2)+3y=21
20+5y+6y/2=21
20+5y+6y=21*2
20+11y=42. (11y=42-22)
11y =22.
y =2.
now on putting y =2 in second equation we will get value of x.
2x-y=4
2x-2=4
2x=4+2
x=6/2=3.
therefore the value of x is 3 and y is 2.



if my answer is helpful for you then please mark as brain liest