+0

# PLZ Help!!!!!

+1
237
2

SHOW WORK PLZ!! SO I CAN LEARN IT BETTER

Sep 26, 2018
edited by Guest  Sep 26, 2018

#1
+111329
+2

1)

4x^2 + 16x  = 48      subtract 48 from both sides

4x^2 + 16x  - 48  = 0      factor out the 4

4(x^2 + 4x - 12)  = 0      divide away the 4

x^2 + 4x - 12   = 0        factor this

(x + 6) ( x - 2)   = 0

Set both factors to 0  and solve for x and we get that   x  = -6   or  x = 2

2)

x^2 + 7x  = -6    add 6 to both sides

x^2 + 7x + 6  = 0    factor the left side

(x + 6) ( x + 1)   = 0

Set both factors to 0  and solve for x and we get that   x  = -6   or  x = -1

Sep 26, 2018
#2
+111329
+2

1)

x^2 - 3x  = 18     subtract  18 from both sides

x^2  - 3x - 18  = 0    factor the left side

(x - 6) ( x + 3)   = 0

Set both factors to 0  and solve for x and we get that   x  = 6   or  x = -3

2)

x^2   - 3x +  ___   =  18  +   ___

Take 1/2 of 3  = 3/2...square this  = 9/4...add to both sides

x^2  - 3x + 9/4  =  18 + 9/4        factor the left side  and simplify the right

(x - 3/2)^2  = 72/4 + 9/4

(x - 3/2)^2  =  81/4         take both roots

x - 3/2  = ±√ [ 81/4]    take the square root on the right

x - 3/2 = ± 9/2     add 3/2 to both sides

x = 3/2 ±9/2   which means that  x  = 3/2 + 9/2  = 12/2  = 6   or   x = 3/2 - 9/2  = -6/2  = -3

Sep 26, 2018