Question

Solve this simultaneous equation?

4x + y = 25
x - 3y = 16

Answer 1

To solve the simultaneous equations, the elimination method was used. After multiplying the second equation by 4 and subtracting the first equation, y = -3 was determined. Substituting y into the first equation gave x = 7.

Step-by-step explanation:

To solve the simultaneous equations 4x + y = 25 and x - 3y = 16, we can use either the substitution method or the elimination method. Here, we'll use the elimination method:

Multiply the second equation by 4 to make the coefficients of x the same: 4(x - 3y) = 4×16, which simplifies to 4x - 12y = 64.

Subtract the first equation from this new equation to eliminate x: (4x - 12y) - (4x + y) = 64 - 25, which simplifies to -13y = 39.

Divide by -13 to solve for y: y = -3.

Substitute y back into the first equation to find x: 4x + (-3) = 25, so 4x = 28 and thus x = 7.

Therefore, the solution to the simultaneous equations is x = 7 and y = -3.

Answer 2

x-3y=16 -> x=16+3y Put this x into the first equation -> 4(16+3y) +y=25 -> 64+12y+y=25 -> 13y=25-64 -> y= -3 Put this y into first or second equation ( it's up to you :) X-3y=16 -> x-3(-3)=16 -> x+9=16 -> x = 7 --->> (7;-3) Good Luck