Step-by-step explanation:
90×3×-5×-2/3×-5
2700/-15
-180
D
Area of a circle is: 兀r✖️r, so 4.1m ➗2 = 2.05, 2.05✖️2.05 = 4.2025
20 percent of the discount minus 5 percent sales tax equals to 15 percent.
know calculate the 15 percentage out of 78,12 so x on 78,12 equals to 20 on 100 so 78,12 equals to 100 percent and x equals to 15 percent so 78,12 times 15 divided by 100 is 15 percent or the number you found discount and and sales tax combined know you substact 15 percent out of your original price.
Answer:
A. Angle 1 and Angle 7
Step-by-step explanation:
Those two are the only angles that when added up, the sum is 180.
Angle 7 and Angle 2 are also congruent, so if Angle two forms a straight line with Angle 1, Angle 7 should be able to do that too.
Solving a system of equations we will see that we need to use <u>40 liters of the 80% acid solution</u>, and the other <u>20 liters are of the 35% acid solution</u>.
<h3>
How many liters of each solution do we need to use?</h3>
First, we need to define the variables:
- x = liters of the 35% acid used.
- y = liters of the 80% acid used.
We know that we want to produce 60 liters of 65% acid, then we have the system of equations:
x + y = 60
x*0.35 + y*0.80 = 60*0.65
(in the second equation we wrote the percentages in decimal form).
To solve this we need to isolate one of the variables in one equation and then replace it in other one, isolating x we get:
x = 60 - y
Replacing that in the other equation:
(60 - y)*0.35 + y*0.80 = 60*0.65
y*(0.80 - 0.35) = 60*(0.65 - 0.35)
y*0.45 = 60*0.30
y = 60*0.30/0.45 = 40
So we need to use <u>40 liters of the 80% acid solution</u>, and the other <u>20 liters are of the 35% acid solution</u>.
If you want to learn more about systems of equations:
brainly.com/question/13729904
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