Answer:
A ) subtract the second equation from the first equation
Step-by-step explanation:
2x + 3y = 7
2x - 4y = -5
subtracting the second equation from the first equation we get,
7y = 12
y=12/7
This is the correct option
If Sandra mixes <em>x</em> L of 65% solution with <em>y</em> L of 90% solution, then the resulting mixture has a total volume of
<em>x</em> + <em>y</em> = 500
litres, and it contains
0.65<em>x</em> + 0.90<em>y</em> = 0.75 (500) = 375
litres of alcohol.
Solve the first equation for <em>y</em> :
<em>y</em> = 500 - <em>x</em>
<em />
Substitute this into the second equation and solve for <em>x</em> :
0.65<em>x</em> + 0.90 (500 - <em>x</em>) = 375
0.65<em>x</em> + 450 - 0.90<em>x</em> = 375
75 = 0.25<em>x</em>
<em>x</em> = 300
Solve for <em>y</em> :
<em>y</em> = 500 - 300
<em>y</em> = 200
So, Sandra should mix 300 L of 65% solution with 200 L of 90% solution.
Answer:

Step-by-step explanation:
<u>Formula for area of rectangle:</u>
= length × width
<u>Area of the smaller rectangle:</u>
length = 7
width = 6
= 7 × 6
= 42
<u>Area of the larger rectangle:</u>
length = 7 + 4 = 11
width = 6 + 2 = 8
= 11 × 8
= 88
<u>Area of the shaded region:</u>
= Area of the larger rectangle - Area of the smaller rectangle
= 88 - 42
= 46
![\rule[225]{225}{2}](https://tex.z-dn.net/?f=%5Crule%5B225%5D%7B225%7D%7B2%7D)
Hope this helped!
<h3>~AH1807</h3>
Answer:
3-Equalateral
Step-by-step explanation:
All the sides are all equal, which basically eliminates isosceles, isosceles acute, and scalene, therefore the answer is Equalateral.