Label each of the following as true, false, or open.

a. –4(5x) = 12

b. 4 x 6 = 24

c. a + 4 = 6, when a = 2.

d. 4x = 19, when x equals 5.

a. –4(5x) = 12; OPEN

b. 4 x 6 = 24; TRUE

c. a + 4 = 6, when a = 2; TRUE

d. 4x = 19, when x equals 5; FALSE

Step-by-step explanation:

a. –4(5x) = 12 [-20x = 12 {Divide -20 from both sides} x = -0.6 So, if x is = -0.6, then it is true, so OPEN.

b. 4 x 6 = 24 [4 x 6 = 24 so TRUE]

c. a + 4 = 6, when a = 2. (Plug 2 in for a) 2 + 4 = 6; 6 = 6; TRUE

d. 4x = 19, when x equals 5. (Plug 5 in for x) 4(5) = 19; 20 is not = 19; FALSE

Step-by-step explanation:

(2x-5)(3x+8)

6x^2-15x+16x-40

6x^2+x-40

(x^2+15x+65)+(6x^2+x-40)

7x^2+16x+25

B)

(4x+1)(3x-4)=12x^2+3x-16x-4=12x^2-13x-4

(12x^2-13x-4)-(5x^2-10x-12)=7x^2-3x+8

D)

(3x+2)(x-5)=3x^2+2x-15x-10=3x^2-13x-10

(8x^2+19x+4)+(3x^2-13x-10)=11x^2+6x-6

A)

(6x+1)(3x-7)=18x^2+3x-42x-7=18x^2-39x-7

(18x^2-39x-7)-(7x^2-34x-20)

11x^2-5x+13

C)