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
1. 15-x
2. 4y
These are algebraic expressions for both.
Answer:
A
Step-by-step explanation:
f(x) = 2x^2 – 3x + 1 is a function (its graph is a parabola that opens up), and it is one-to-one (Answer A). For each input, x, this function will return one output.
Answer:
55 square miles
Step-by-step explanation:
A=7*10/2+10*4/2
=35+20
=55
Answer:
12 sales
Step-by-step explanation:
Let x represent the number of sales each man had.
For Salesman A, he earns $65 per sale; this is 65x.
For Salesman B, he earns $40 per sale; this is 40x. We also add to this his weekly salary of $300; this gives us 40x+300.
Since their pay was equal, set the two expressions equal:
65x = 40x+300
Subtract 40x from each side:
65x-40x = 40x+300-40x
25x = 300
Divide both sides by 25:
25x/25 = 300/25
x = 12
