Hey there :)
Let
p represent the number of bags to be bought
We need to collect
30 stickers and each
bag has
3 stickers
3p = 30
↑ ↑
Number of stickers in a bad Number of stickers to be collected
=
p = 10We need to buy 10 bags of crisps to have 30 stickers
For every second the water runs it rises 15 mm and the slope of the graph is 15.
Let s be the cost of one shirt and t, the cost of 1 tie
Then:
(a) 3.s + 5.t = 60
(b) 2.s + 3.t = 39
Solve this equation by elimination:
<span> Let's eliminate t. To that end you multiply all the terms of (a) by negative 3 and all the terms of (b) by positive 5
</span>(a) 3.s + 5.t = 60→→ (-3).(3.s+5.t) → - 9.s - 15.t = -180(c)
(b) 2.s + 3.t = 39→→ (+5).(2.s+3.t) → +10.s + 15.t = 195 (d)
Now you add (c) + (d) → s= $15 , This is the cost of 1 shirt. To find the cost of 1 tie, you replace s by 5 in any of the equation, say (b):
(b) <span>2.s + 3.t = 39 </span>→ 2.(15) + 3t = 39 → 30+3t = 39 and 3t =39-30 = 9
So 3t = 9 and t = $3 (price of 1 tie)
Jill has three crayons and Jeff has eight crayons. 3 + 5 = 8