Let Billy have x common cards, and y premium cards:
(i) Billi has 124 cards:
x+y=124
(ii) the total value of the cards is 81.50$:
0.5x $ + 1.00*y $= 81.50 $, so
0.5x+y=81.5
we can write y=81.5-0.5x and substitute in (i):
x+y=124
x+(81.5-0.5x )=124
x+81.5-0.5x=124
x-0.5x=124-81.5
0.5x=42.5
x=42.5/0.5=85
y=124-85=39
Answer: Billy has 85 common cards and 39 premium cards
Answer:
4x -3y = -12
Step-by-step explanation:
We need the slope and the y intercept
It crosses the y axis at y =4 so the y intercept is 4
(0,4)
We need another point to help us find slope
Another point is (-3,0)
We have 2 points we can find slope using
m = (y2-y1)/ (x2-x1)
= (0-4)/(-3-0)
=-4/-3
=4/3
The slope 4/3 and the y intercept is 4
y = mx+b
y = 4/3 x+4
Multiply by 3
3y = 3*4/3x + 3*4
3y =4x+12
Subtract 4x from each side
-4x+3y = 4x-4x+12
-4x+3y =12
Multiply by -1
4x -3y = -12
1_ 210+90= 300
2_ it's prime:
[1,19]
good luck
Just add them together. For example if you have 4x and 7x you would just do 4x+7x and get 11x. You can only add them because they are like terms, meaning that they share a variable.