Answer:
-12
Step-by-step explanation:
Note that when x < 6, you will use the expression -4x
f(x) = -4x
Plug in 3 for x
f(3) = -4(3)
Simplify. Multiply
f(3) = -4(3)
f(3) = -12
-12 is your answer
Answer:
45 cm
Step-by-step explanation:

One at 100,18 one at 200,14 one at 150,15 one at 125,20 and one at 225,12
Equation 1) x + 6y = 2
Equation 2) 5x + 4y = 36
Multiply all of equation 1 by 5.
1) 5(x + 6y = 2)
Simplify.
1) 5x + 30y = 10
2) 5x + 4y = 36
Subtract equations from one another.
26y = -26
Divide both sides by 26.
y = -1
Plug in -1 for y in the first equation.
x + 6y = 2
x + 6(-1) = 2
Simplify.
x - 6 = 2
Add 6 to both sides.
x = 8
D : (8, -1)
~Hope I helped!~