There are 18 girls in the class and 6 boys.
You can make a proportion of 8/20 to 42/x and then simply cross multiply from there to solve for y
Answer: 1045 cm of red ribbon and 1045 cm of yellow ribbon
<u>Step-by-step explanation:</u>
Let R represent the amount red ribbon and Y represent the amouont of yellow ribbon.
- bought the same lengths of red and yellow: R = Y
- after used 286 of red, yellow is 5 times the remaining red; 5(R - 836) = Y
Use substitution method to solve:
5(R - 836) = R
5R - 4180 = R <em>distributed 5 on the left side</em>
4R - 4180 = 0 <em>subtracted R from both sides</em>
4R = 4180 <em>added 4180 to both sides</em>
R = 1045 <em>divided both sides by 4</em>
40 times 3/3+5= Niamh’s amount = 40x3/8 = 15 pencils
40 times 5/3+5= Jack’s amount =
40x5/8 = 25 pencils
<span>x=<span>−<span><span>2<span> and </span></span>y</span></span></span>=<span>−<span>2
</span></span>A.(−2, −2)
