Question

4x^2 = 92 + 7x solve the equation using the guadratic formula, show all work

Answer 1

`4x^2=92+7x\ \ \ \ |-4x^2\\\\-4x^2+7x+92=0\\\\a=-4;\ b=7;\ c=92\\\\b^2-4ac=7^2-4\cdot(-4)\cdot92=49+1472=1521\\\\√(b^2-4ac)=√(1521)=39\\\\x_1=(-b-√(b^2-4ac))/(2a);\ x_2=(-b+√(b^2-4ac))/(2a)\\\\x_1=(-7-39)/(2\cdot(-4))=(-46)/(-8)=(23)/(4)\\\\x_2=(-7+39)/(2\cdot(-4))=(32)/(-8)=-4`



`\text{Answer:}\ A.\ \left\{(23)/(4);\ -4\right\}`