y-intercept: when x = 0
for line a:
y = 0 + 7 = 7
for line b:
when x = 0, the value is -5
7 > -5, so y-intercept of line a is greater than line b's.
john multiplied the second equation by 4.
we are given two linear equations and we know that john multiplied the first equation by -3 and the second equation by another number to eliminate the x-terms.
we are to find that another number.
multiplying the first equation by -3 we get:
-12x + 18y = -6 (3)
since we have to eliminate the x terms so coefficients of x must be the same with opposite signs. so we need 12x in the second equation to eliminate it.
for this, we need to multiply the second equation by 4 to get:
12x + 20y = 44