Solve the system of equation by graphing.

Question

What is the solution of the system of equations? Select the correct choice below and, if necessary, fill in the answer box to complete your choice.

____(type the order pair)

Answer 1

ax + by = c

dx + ey = f

multiply 1st equation by d, 2nd by a and subtract to eliminate one variable

adx +dby = cd

adx +aey = af

y(db-ae) = dc-af

y = (dc-af)/(db-ae)

x = (c-by)/a = [c-(bcd-abf)/db^2-aeb]/a

If you have a system of two linear equations, plug in the values of a,b,c,d,e, and f into the above formulas for x and y

ax+by = c, solve for y

y= (c-ax)/b = c/b -ax/b It is a straight line with slope=-a/b and y intercept = c/b

dx +ey = f, solved for y is

y=f/e -dx/e another straight line with slope =-d/e and y intercept= f/e