Question

(x+7)(x-3)=-7
what is the answer of this ​??

Answer 1

Step-by-step explanation:

x2 - 3x + 7x - 21 = -7

x2 + 4x - 21 = -7

x2 + 4x - 21 + 7 = 0

x2 + 4x - 14 = 0

so a=1, b=4, and c=-14

x = (-b ± √(b2 - 4ac)) / 2a = (-4 ± √(42 - 4*1*-14)) / 2*1 = (-4 ± √(16 + 56)) / 2 = (-4 ± √(72)) / 2

= (-4 ± √(36*2)) / 2 = (-4 ± 6√2) / 2 = -2 ± 3√2

Answer 2

Answer:

x=-2 ± 3√2

Step-by-step explanation:

(x+7)(x-3)=-7

x²-3x+7x-21=-7

x²+4x-14=0

x=  { -4 ±√(4²+4*14) }/2

= { -4 ±√72 }/2

= { -4 ±6√2 }/2

x=-2 ± 3√2