Answer:
x=1 and y=4/5
Step-by-step explanation:
<u>Given system of equations</u>
3x+5y=7
5x+10y=13
<u />
<u>Multiply first equation by 2</u>
2(3x+5y)=2(7)
6x+10y=14
<u>Eliminate y-variable to get "x"</u>
6x+10y=14
<u>- 5x+10y=13</u>
x = 1
<u>Substitute x=1 into either equation and find "y"</u>
3x+5y=7
3(1)+5y=7
3+5y=7
5y=4
y=4/5
Therefore, x=1 and y=4/5
Answer: B. (-6, 5)
Step-by-step explanation:
Answer:
10.6
Step-by-step explanation:
4 + 6(1.3) - 2.4 * 0.5
= 4 + 6 * 1.3 - 2.4 * 0.5
= 4 + 7.8 - 0.5 * 2.4
= 4 + 7.8 - 1.2
= 10.6
Answer:
15/4 and 45/4
Step-by-step explanation:
Let x and y be the numbers
x = 3y
x+ y = 15
Substitute the first equation in to the second equation
3y+y = 15
4y = 15
y = 15/4
x = 3(15/4)
x = 45/4
The two numbers are 15/4 and 45/4
Answer:
<em><u>A.10000</u></em>
<em><u>B.25 more trees must be planted</u></em>
Step-by-step explanation:
⇒Given:
- The intial average yield per acre
= 150
- The initial number of trees per acre
= 100
- For each additional tree over 100, the average yield per tree decreases by 1 i.e , if the number trees become 101 , the avg yield becomes 149.
- Total yield = (number of trees per acre)
(average yield per acre)
<em>A.</em>
⇒If the total trees per acre is doubled , which means :
total number of trees per acre
=
= 200
the yield will decrease by :
- 

⇒total yield = 
<em>B.</em>
⇒to maximize the yield ,
let's take the number of trees per acre to be 100+y ;
and thus the average yield per acre = 150 - y;
total yield = 
this is a quadratic equation. this can be rewritten as ,
⇒ 
In this equation , the total yield becomes maximum when y=25;
<u><em>⇒Thus the total number of trees per acre = 100+25 =125;</em></u>