Y=3x+4

x+4y=-10

solve for substitution

Y=3x+4 ... eq. (i) x+4y=-10 ... (eq. ii) putting value of y in eq. (ii), we get, x+4 (3x+4) = - 10 or x+12x+16=-10 or, 13x=-10+16 or, 13x=6 ●#x=6:13 putting value if x in eq. (i), we get y=3 (6:13) + 4 or, y=18:13+4 or, y = (18+52) : 13 ●#y=70:13