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2 years ago

If a class of 30 students have to split the boys and girls in hafe and 10% are girls, how meany girls are in the class

Mathematics

1 answer:

Anit [1.1K]2 years ago

6 0

Answer:

10 girls

Step-by-step explanation:

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A chemical company makes two brands of antifreeze. The first brand is 20% pure antifreeze, and the second brand is 70% pure anti

andre [41]

Answer:

First brand of antifreeze: 21 gallons

Second brand of antifreeze: 9 gallons

Step-by-step explanation:

Let's call A the amount of first brand of antifreeze. 20% pure antifreeze

Let's call B the amount of second brand of antifreeze. 70% pure antifreeze

The resulting mixture should have 35% pure antifreeze, and 30 gallons.

Then we know that the total amount of mixture will be:

$A + B = 30$

Then the total amount of pure antifreeze in the mixture will be:

$0.2A + 0.7B = 0.35 * 30$

$0.2A + 0.7B = 10.5$

Then we have two equations and two unknowns so we solve the system of equations. Multiply the first equation by -0.7 and add it to the second equation:

$-0.7A -0.7B = -0.7*30$

$-0.7A -0.7B = -21$

$0.2A + 0.7B = 10.5$

--------------------------------------

$-0.5A = -10.5$

$A = \frac{-10.5}{-0.5}$

$A = 21\ gallons$

We substitute the value of A into one of the two equations and solve for B.

$21 + B = 30$

$B = 9\ gallons$

3 0

2 years ago

PLEASE HELP ITS DUE TODAY!!! Write an equation in which the quadratic expression 2x^2-2x 12 equals 0. Show the expression in fac

stepladder [879]

This is the function

${2x}^{2} - 2 {x}^{1} + 12$

Then factor 2 out

$2(x^2- x + 6) = 0$

Divide both side by two and use the quadratic formula to get the following

$(x - 3)(x + 2) = 0$

X=3 And x=-2 and don't forget to Chek them

3 0

3 years ago

Help me pls pls pls

lara31 [8.8K]

Answer:

1,3

Step-by-step explanation:

1,3

4 0

2 years ago

Read 2 more answers

20 pointss please help I appreciate it <333

ivanzaharov [21]

Answer:

DE = 7.07 RS = 11.04 not congruent

Step-by-step explanation:

Formula:

$d=\sqrt{(x2-x1)^2 + (y2-y1)^2}$

D (5,0) E (0,-5)

$d=\sqrt{(0-5)^2 + ( -5 - 0)^2}$

$d=\sqrt{(-5)^2 + (-5)^2}$

$d=\sqrt{25+25}$

$d=\sqrt{50}$

d= 7.07

R (-5,-5) S (6,-6)

$d=\sqrt{(6-(-5))^2 + (-6 - (-5))^2 }$

$d=\sqrt{11^2 + (-1)^2}$

$d=\sqrt{121 + 1}$

$d=\sqrt{122}$

d= 11.04

3 0

2 years ago

Pls help me with my testt

Nitella [24]

Answer:

slope

Step-by-step explanation:

wisusushsheusueueheyehuee

5 0

2 years ago