Question

| 2x + 3 | = 15
4x^2 + x - 3 = 0

Answer 1

1)

$|2x + 3| = 15 \\ \\ 2x + 3 = 15 \\ - 2x - 3 = 15 \\ \\ 2x = 12 \\ - 2x = 18 \\ \\ x = 6 \\ x = - 9$

2)

$4 {x}^{2} + x - 3 = 0 \\ d = 1 + 48 = 49 \\ \sqrt{d} = 7 \\ x = \frac{1 + - 7 }{8} \\ \\ x = \frac{ - 1 + 7}{8} = 0.75 \\ x = \frac{ - 1 - 7}{8} = -1$

Answer 2

1) 2x+3=15

2x=12

x=6

2x+3=-15

2x=-18

x=-9

2) D=1-4*(-3)*4=49

x1=(-1+7)/2*4 = 6/8=3/4

x2=(-1-7)/2*4=-8/8=-1