Question

quickly tell this..emergency..the 3rd one with bracket​

Answer 1

Answer:

Use completing the Square Method to make the 3 equations perfect squares and take square root

Answer 2

(2x^2+11x-21) x=-7 or x=3/2

Step-by-step explanation:

by factorisation method

first the x term has 2 as coefficient as a result we will multiply (-21) with 2 we will get (-42)

then we need to find such factors of -42 their substraction is +11

these numbers are (+14) and (-3)

2x^2+11x-21

2x^2+14x-3x-21

we will take common

2x(x+7)-3(x+7)

(x+7) (2x-3)

x+7=0 or 2x-3=0

x= -7 or x=3/2