Solve the following system:
{1.8 x - 0.5 y = -6.4
{0.6 x + 2.1 y = 2.4
In the first equation, look to solve for x:
{1.8 x - 0.5 y = -6.4
{0.6 x + 2.1 y = 2.4
1.8 x - 0.5 y = (9 x)/5 - y/2 and -6.4 = -32/5:
{(9 x)/5 - y/2 = -32/5
Add y/2 to both sides:
{(9 x)/5 = 1/10 (5 y - 64)
{0.6 x + 2.1 y = 2.4
Multiply both sides by 5/9:
{x = 1/18 (5 y - 64)
{0.6 x + 2.1 y = 2.4
Substitute x = 1/18 (5 y - 64) into the second equation:
{x = 1/18 (5 y - 64)
{2.1 y + 0.0333333 (5 y - 64) = 2.4
2.1 y + 0.0333333 (5 y - 64) = 2.1 y + (0.166667 y - 2.13333) = 2.26667 y - 2.13333:
{x = 1/18 (5 y - 64)
2.26667 y - 2.13333 = 2.4
In the second equation, look to solve for y:
{x = 1/18 (5 y - 64)
{2.26667 y - 2.13333 = 2.4
2.26667 y - 2.13333 = (34 y)/15 - 32/15 and 2.4 = 12/5:
(34 y)/15 - 32/15 = 12/5
Add 32/15 to both sides:
{x = 1/18 (5 y - 64)
{(34 y)/15 = 68/15
Multiply both sides by 15/34:
{x = 1/18 (5 y - 64)
y = 2
Substitute y = 2 into the first equation:
Answer: {x = -3, y = 2
There is a 8oz difference, and a $4.20 difference, causing store 1 to be the better deal
Answer: 7 over 3
Step-by-step explanation: 7/9 x 3
7 x 3 over 9 Simplify 7 x 3 and that’s 21 so now you have 21 over 9. Then you simplify 21 over 9 and you get 7 over 3
Y=5x+3
y=4x+6
5x+3=4x+6
5x-4x=6-3
x=3
y=5(3)+3
y=15+3
y=18
Answer:
(C) 5
Step-by-step explanation:
x+7=2y
<em>Subtract 7 from both sides</em>
x=2y-7
2y-7=x
<em>Multiply both sides by 2</em>
4y-14=2x
y=2x−1
<em>Add 1 to both sides</em>
y+1=2x
<u>Combine equations:</u>
y+1=4y-14
<em>Add 14 to both sides</em>
y+15=4y
<em>Subtract y from both sides</em>
15=3y
3y=15
<em>Divide both sides by 3</em>
y=5
<u>The answer is </u><u>(C) 5.</u>