Question

Find the value of x and y from the following equations x+y =20 and 30x +70y =180

Answer 1

x+y=20...eq1 30x+70y=180 divide eq by 10 3x+7y=18...eq2 Frm eq1 put x=20-y in eq2 3(20-y)+7y=18 60-3y+7y-18=0 42+4y=0 4y=-42 Y=42/4=21/2 X= 20-21/2 = 40-21/2 = 11/2