Final answer:
To solve the system of equations using the linear combination method, we need to eliminate one of the variables by multiplying the equations by suitable constants.
Step-by-step explanation:
To solve the system of equations using the linear combination method, we need to eliminate one of the variables by multiplying the equations by suitable constants so that the coefficients of one of the variables will add up to zero when the equations are added. Let's multiply the first equation by 4 and the second equation by 7 to get:
12x + 28y = 124
-21y - 14y = -7
Now, add the two equations:
12x + 28y - 21y - 14y = 124 - 7
Combining like terms:
12x - 7y = 117
Dividing both sides of the equation by 12, we get:
x = 117/12 = 9.75
Therefore, the value of x is 9.75.