4c+5.6d=1360
Let
Children (c)=x
Adults (d)=284-x
4x+5.6 (284-x)=1360
Solve for x
4x+1590.4-5.6x=1360
4x-5.6x=1360-1590.4
-1.6x=-230.4
X=230.4÷1.6
X=144 children
284−144=140 adults
You should write numbers in as many ways as you possibly can to make new connections in your brain. Knowing how to write numbers in many different ways can help you solve complex problems more easily. Doing this can also reinforce the mathematical principles and logic you have memorised.
Writing one in many different ways:
1=1/1=2/2=3/3=4/4=(-1)/(-1)=(-2)/(-2)
=1.0=1.00=1.000=(1/2)+(1/2)=(1/3)+(1/3)+(1/3)
=(1/4)+(1/4)+(1/4)+(1/4)
Writing a half in many different ways:
1/2=(1/4)+(1/4)=(1/6)+(1/6)+(1/6)
=(1/8)+(1/8)+(1/8)+(1/8)=4*(1/8)
=2/4=3/6=4/8=5/10=0.5=0.50
etc...etc...
Let's factor the top and the bottom.
Top factors 4x + 20 = 4(x + 5)
Bottom x^2 + 2x - 15 = (x + 5)(x - 3)
The gcf is the largest value that will go into both the top and the bottom. In our problem the ONLY thing that will go into top and bottom is x + 5 so that is your GCF. (c)
The plumber worked for 5 hours because 450-200=250 which gets rid of the initial fee so 250 divided by 50 is 5
