S+f=24 s=3f

I need this now

f=6 and s=18

Step-by-step explanation:

Let's solve your system by substitution.

s+f=24;s=3f

Rewrite equations:

s=3f;f+s=24

Step: Solves=3ffor s:

s=3f

Step: Substitute3fforsinf+s=24:

f+s=24

f+3f=24

4f=24(Simplify both sides of the equation)

4f

4

=

24

4

(Divide both sides by 4)

f=6

Step: Substitute6forfins=3f:

s=3f

s=(3)(6)

s=18(Simplify both sides of the equation)

f=6 and s=18

£56

step-by-step explanation:

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