Question

4x
$(4x) {?}^{2} + 25x - 36$
​

Answer 1

Answers:

$\huge{\boxed{\boxed{\sf{x=-4\:and\frac{-9}{4}}}}}$

step-by-step explanation:

$\huge{\boxed{\boxed{\underline{\sf{SOLUTION-}}}}}$

>> CORRECTION IN QUESTION:

$(4x)^{2} + 25x + 36$

>> WE HAVE TO FIND THE VALUES OF X:

>> SO WE USE TWO METHODS TO FIND THE VALUES OF X

$\huge{\boxed{\boxed{\underline{\sf{METHOD(1)-}}}}}$

$middle \: term \: spliting\\ = )4 {x}^{2} + 25x + 36 = 0\\ = )4 {x}^{2} + 16x + 9x + 36 = 0 \\ = )4 x(x + 4) + 9(x + 4) = 0 \\ = )(4x + 9)(x + 4) = 0 \\ = )4x + 9 = 0 \\ = )4x = - 9 \\ = )x = \frac{ - 9}{4} -----1st\:zeroes \\ = )x + 4 = 0 \\ = )x = - 4-----2nd\:zeroes$

$\huge{\boxed{\boxed{\underline{\sf{METHOD(2)}}}}}$

$d = {b}^{2} - 4ac \\ d = {25}^{2} - 4 \times 4 \times 36 \\ d =625 - 576 \\ d = 49 \\ again \\ x = \frac{ - b + \sqrt{d} }{2a} \\ x = \frac{ - 25 + 7}{2 \times 4} \\ x = \frac{ - 18}{8} \\ x = \frac{ - 9}{4} - - - - - 1st \: zeroes \\ x = \frac{ - b - \sqrt{d} }{2a} \\ x = \frac{ - 25 - 7}{2 \times 4} \\ x = \frac{ - 32}{8} \\ x = - 4 - - - - - 2nd \: zeroes$

$\huge{\boxed{\boxed{\sf{x=-4\:and\frac{-9}{4}}}}}$