Expand and simplify (x+3)(x-4)

xsquared (x3)-(x4,) your welcome

Step-by-step explanation:

Use FOIL method.

F - First ; O - Outside ; I - inside ; L - last

(x + 3)(x - 4) = x*x + x*(-4) + 3*x + 3*(-4)

                  = x² - 4x + 3x - 12

                  = x² - x  - 12

-4

step-by-step explanation:

(-4+8)=-(4-8)=-8+4=-4

a 4/6 = 9/12   not proportional

step-by-step explanation:

to find which are not proportional, we can use cross products

if it is true, they are proportional.   if it is not true, they are not proportional.

a 4/6 = 9/12

4* 12 = 6*9

48 = 54

not this is not proportional  

b 2/3 = 12/18  

2* 18 = 3 * 12

36 = 36

this is proportional

c 5/4 = 10/8  

5*8 = 4*10

40 = 40

this is proportional

d 7/5 = 35/25

7*25 = 5 * 35

175 = 175

is proportional