Question

solve 2x+3y=77;3x+5y=124 by substitution method

Answer 1

2x+3y =77

⇒2x=77-3y
⇒x=(77-3y)/2 ------(1)
3x+5y=124---(2)

plug (1) in (2)

3[77-3y]/2 +5y =124

3(77-3y) +10y = 2*124

231 -9y +10y = 248
y = 248-231
y=17

plug y=17 in (1)

x = (77 - 3*17)/2

x= (77 -51)/2

x= 26/2
x=13
therefore
x= 13 and y=17