Given:
15 students
2 students must be chosen.
No repetition, no order
This is a combinations problem. We use this formula: n! / (n-r)!(r!)
n = 15 ; r = 2
15! / (15-2)!(r!) ⇒ 15! / 13! * 2! = 105
Answer:
<em>x = -2, y = -1</em>
Step-by-step explanation:
<u>System of Equations</u>
Solve the system:
y = 1/2x
y = -x - 3
Multiplying the first equation by 2:
2y = x
Substituting x in the second equation:
y = -2y - 3
Adding 2y:
3y = -3
y = -3/3
y = -1
And x = 2*(-1) = -2
Solution: x = -2, y = -1
Answer:
Smoothie = 3
Ice cream = 1.5
Step-by-step explanation:
2s + i = 7.5
3s + 2i = 12
subtract the equations
(3s + 2i) - (2s + i) = s + i
s + i = 4.5
2s + i = 7.5, so s must equal 3 (7.5 - 4.5)
If s = 3, then i is 1.5 (4.5 - 3.5)
To check, plug 3 and 1.5 into s and i.
2(3) + 1.5 = 7.5
6 + 1.5 = 7.5
7.5 = 7.5
3(3) + 2(1.5) = 12
9 + 3 = 12
12 = 12
116/21 hope this helped !
Slope-intercept form: y=mx+b
3y=-6+2x
divide both sides by 3
y=-2+2/3x
reorder the terms
y=2/3x-2
