X = pencils, y = pens
8x + 6y = 8.50
4x + 4y = 5.....multiply by -2
----------------
8x + 6y = 8.50
-8x - 8y = -10 (result of multiplying by -2)
-----------------add
-2y = - 1.50
y = -1.50 / -2
y = 0.75 <=== pens cost 0.75
4x + 4y = 5
4x + 4(0.75) = 5
4x + 3 = 5
4x = 5 - 3
4x = 2
x = 2/4
x = 0.50 <== pencils cost 0.50
Answer:O_O
Step-by-step explanation:
In 8 weeks the reef grows 13 m, or 104 m.
Converting 104 m into mm:
104 m 1000 mm
--------- * ------------- = 104,000 mm
1 1 m
Answer:
12
Step-by-step explanation:
The answer is y = 35x + 20.
In order to find this, start with two ordered pairs. For the purpose of this problem, we'll use (1, 55) and (2, 90). Now we use the slope formula to find the value next to x in the equation.
m(slope) = (y2 - y1)/(x2-x1)
In this equation (x1, y1) is the first ordered pair and (x2, y2) is the second. Plug in to the equation and solve.
m = (90 - 55)/(2 - 1)
m = 35/1
m = 35
Now that we have the slope, plug that into the equation along with either point to find the intercept (the last number).
y = mx + b
55 = 35(1) + b
55 = 35 + b
20 = b
Now that we have the slope and intercept, we can use each to fill in those blanks.
y = 35x + 20
