Answer:
40
Step-by-step explanation:
Answer:
- <u>120 pens and 200 pencils.</u>
<u></u>
Explanation:
You can set a system of two equations.
<u>1. Variables</u>
<u />
- x: number of pens
- y: number of pencils
<u>2. Cost</u>
- <em>each pen costs</em> $1, then x pens costs: x
- <em>each pencil costs</em> $0.5, then y pencil costs: 0.5y
- Then, the total cost is: x + 0.5y
- The cost of the whole purchase was $ 220, then the first equation is:
x + 0.5y = 220 ↔ equation (1)
<u>3. </u><em><u>There were 80 more pencils than pens</u></em>
Then:
pencils = 80 + pens
↓ ↓
y = 80 + x ↔ equation (2)
<u>4. Solve the system</u>
i) Substitute the equation (2) into the equation (1):
ii) Solve
iii) Substitute x = 120 into the equation (2)
Solution: 120 pens and 200 pencils ← answer
Answer: (a, 0)
<u>Step-by-step explanation:</u>
Notice that S is on the x-axis, therefore the y-coordinate is "0".
Notice that S has the same x-value of R. The x-value of R is "a".
Answer:
y=-x-2
Step-by-step explanation:
To find the slope of the line, you can use the slope formula. I did this with (-3,1) and (2,-4) to get: (1+4)/(-3-2). This ends up as -5/5, which simplifies to -1.
next I plugged in the slope and one point into the line equation: y=mx+b. I plugged in (-4)=(-1)(2)+b. This equated to b=-2.
Check Work:
The equation -4=(-1)(2)-2 is true
The equation 1=(-1)(-3)-2 is true
Answer:
-16x+14.8
Step-by-step explanation:
2(x+7)-2(9x-0.4)
2x+14-18x+0.8
-2x+14-18x+0.8
14-16x+0.8
14+0.8-16x
14.8+-16x
