Respuesta :
Answer:
( 7 , 4 )
given:
- 4x + 10y = 68
- 4x - y = 24
make y the subject in equation 2:
4x - y = 24
-y = 24 - 4x
y = 4x - 24
insert this in equation 1:
4x + 10y = 68
4x + 10(4x - 24) = 68
4x + 40x - 240 = 68
44x = 68 + 240
44x = 308
x = 7
solve for y:
y = 4x - 24
y = 4(7) - 24
y = 4
4x + 10y =68 ......(1)
4x - y = 24 .......(2)
From equation (2)
y = 4x - 24 .....(3)
Put Eqn (3) into Eqn (1)
4x + 10(4x - 24)=68
4x + 40x -240 = 68
44x - 240 = 68
44x = 68 + 240
44x = 308
Divide through by 44
x = 7
Put x = 7 in Eqn(3)
y = 4(7) -24
y = 28 -24
y = 4
(x,y) = (7 , 4)
4x - y = 24 .......(2)
From equation (2)
y = 4x - 24 .....(3)
Put Eqn (3) into Eqn (1)
4x + 10(4x - 24)=68
4x + 40x -240 = 68
44x - 240 = 68
44x = 68 + 240
44x = 308
Divide through by 44
x = 7
Put x = 7 in Eqn(3)
y = 4(7) -24
y = 28 -24
y = 4
(x,y) = (7 , 4)