8.9 x 10^-5 in scientific notation
Answer:
y=-1/3x-6.. .. .. .. .. ..
<u><em>1- Writing the system of equations:</em></u>
The price of a cup of coffee is denoted by c while the price of a spaghetti is denoted by s
<u>We are given that:</u>
4 cups of coffee and 6 spaghetti cost $20.5
<u>This means that:</u>
4c + 6s = 20.5 ................> equation 1
<u>We are also given that:</u>
1 cup of coffee and 3 spaghetti cost $8.75
<u>This means that:</u>
c + 3s = 8.75 .................> equation 2
<em><u>2- Solving the equations using substitution methods:</u></em>
<u>From equation 2:</u>
c = 8.75 - 3s ................> I
<u>Substitute with I in equation 1 and solve for s as follows:</u>
4c + 6s = 20.5
4(8.75 - 3s) + 6s = 20.5
35 - 12s + 6s = 20.5
35 - 6s = 20.5
6s = 14.5
s = $2.41667
<u>Substitute with s in I to get c:</u>
c = 8.75 - 3s
c = 8.75 - 3(2.41667) = 1.4999 = $1.5
<u><em>3- getting price for 1 cup of coffee and 1 spaghetti:</em></u>
c + s = 1.5 + 2.41667 = $3.91667
Hope this helps :)
