Answer:
;-;
Step-by-step explanation:
4.5x + 1.5y = 24 ⇒ 4.5x + 1.5y = 24
1.0x - 1.0y = 4 ⇒<u> 4.5x - 4.5y = 18</u>
<u>6y</u> = <u>6</u>
6 6
y = 1
4.5x + 1.5(1) = 24
4.5x + 1.5 = 24
<u> - 1.5 - 1.5</u>
<u>4.5x</u> = <u>22.5</u>
4.5 4.5
x = 5
(x, y) = (5, 1)
9 dived by 3 = 3
so he surfed for 3 hours = 1/3 of 9
and there are 6 hours left
so he spent 6 hours building a sandcastle