Question

7x²+3x-4=0 solve by completing square method​

Answer 1

7x^+3x-4

= 7x^+7x-4

• -""&+;'_6+;'&-7

= thank you

Answer 2

Answer:

Step-by-step explanation:

we know

(a+b)² = a² + b² + 2ab

7x² + 3x + 4 = 0

divide whole eq. by 7

x² + (3/7)x + (4/7) = 0

now see the middle term multiply and divide it by 2

x² + 2(3/14)x + 4/7 = 0

(x + √(3/14))² = x² + 3/14 + 2√(3/14)x

so add and subtract 3/14in the original eq, we get

x² + 2(3/14)x + 4/7 + 3/14 - 3/14 = 0

rearranging terms

(x² + 2(3/14)x + 3/14) + (4/7 - 3/14) = 0

(x+√(3/14))² + 5/14 = 0

(x+√(3/14))² - i²(√(5/14)) = 0

(x+√(3/14))² - (i√(5/14)) = 0

now use a²-b²=(a-b)(a+b)

(x+√(3/14) - i√(5/14))(x+√(3/14)+i√(3/14)) = 0

therefore,

x= -√(3/14) + i√(5/14) and -√(3/14) - i√(5/14)