Question 324550
{{{x^2+7x=18}}} first-subtract 18 from both sides
{{{x^2+7x-18=0}}} then factor-look for 2 numbers that mult to -18 and add or subtract to get +7. They are +9 and -2.
{{{(x+9)(x-2)=0}}} then set each factor equal to zero
{{{(x+9)=0 and (x-2)=0}}} finally, solve each equation (sub 9 from both sides, add 2 to both sides)
{{{x=-9 and x=2}}} 
to check, substitute -9 for x and 2 for x.
{{{(-9)^2+7(-9)=18}}}
{{{81-63=18}}}
{{{(2)^2+7(2)=18}}}
{{{4+14=18}}}