All categories

3 years ago

If you know help me please I’m stuck!

Mathematics

1 answer:

salantis [7]3 years ago

7 0

Answer:

82.4

Step-by-step explanation:

divide 51/13, multiply that result by 21.

You might be interested in

My number is an even number. my number is greater than 7,200. My number is?

hjlf

Answer:

for the even number your answer would be 7,316

Step-by-step explanation:

an even number always needs to end with an even number

7 0

3 years ago

Please come and help really quick please thank you

professor190 [17]

Answer:

1: 6

2: The initial amount of water in the fountain

3: The amout of water in the fountain over an amount of time

4: y= 3/2x+6

Step-by-step explanation:

7 0

3 years ago

Indicate If these triangles are SSS SAS SAA ASA HL or none

Setler79 [48]

In the two triangles, all the three sides are congruent to the corresponding sides of the other triangle. And in such case, the criteria used for congruency is Side Side Side or SSS .

So the correct option is the first option .

4 0

3 years ago

Find the roots of:

Elena-2011 [213]

$\large\displaystyle\text{$\begin{gathered}\sf \pmb{1) \ 2x^3-7x^2+8x-3=0 } \end{gathered}$}$

Synthetic division is used since the equation is of the third degree. The divisors of -3 are 1, -1, 3, +3. So:

| 2 -7 8 -3

1 | 2 -5 3

| 2 -5 3 0

1 | 2 -3

2 -3 0

So the factorization is (x-1)² (2x-3)=0. So:

$\bf{ x_1=x_2=1 \qquad x_2=\dfrac{3}{2} }$

$\large\displaystyle\text{$\begin{gathered}\sf \pmb{2) \ x^3-x^2-4=0 } \end{gathered}$}$

Synthetic division is used since the equation is of the third degree. The divisors of -4 are 1, -1, 2, -2, 4, -4. So:

| 1 -1 0 -4

2 | 2 2

1 2 2 0

So the factorization is (x-2)(x²+x+2)=0 . When calculating the discriminant of the trinomial, it is concluded that it has no roots since the result is negative. So you only have one solution.

$\bf{ 1^2-4(2)(2)=1-16=-15 < 0 \quad \Longrightarrow \quad x=2 }$

$\large\displaystyle\text{$\begin{gathered}\sf \pmb{3) \ 6x^3+7x^2-9x+2=0 } \end{gathered}$}$

Synthetic division is used since the equation is of the third degree. The divisors of 2 are 1, -1, 2, -2. So:

| 6 7 9 2

-2 | -12 10 -2

6 -5 1 0

So the factorization is (x+2)(6x²-5x+1)=0 . The quadratic equation is solved by the general formula:

$\bf{ x_{2, 3}&=\dfrac{5\pm \sqrt{(5)^2-4(6)(1)}}{2(6)}=\dfrac{5\pm \sqrt{25-24}}{12}=\dfrac{5\pm 1}{12} }}$

$\large\displaystyle\text{$\begin{gathered}\sf \begin{matrix} x_1=-2&\ \ \ \ \ \ x_{2}=\dfrac{6}{12} \qquad &\ \ \ x_3=\dfrac{4}{12}\\ &\ \ \ x_2=\dfrac{1}{2} \qquad &x_3=\dfrac{1}{3} \end{matrix} \end{gathered}$}$

6 0

2 years ago

A chemist wishes to mix a 30% acid solution with a 65% acid solution to obtain 175 quarts of 55% acid solution . How many quarts

Eva8 [605]

x = quarts of 30% acid solution

y = quarts of 65% solution

x + y = 175

Each quart of the 30% solution contributes 0.30x quarts of acid; similarly, each quart of the 65% solution contributes 0.65y quarts of acid. So

0.3x + 0.65y = 0.55*175 = 96.25

That is, the chemist wants 175 quarts of a new mixture with a 55% concentration of acid, which comes out to 95.25 total quarts of acid. The total amounts of acid from either sides of this equation must balance out.

Now solve for x and y:

x + y = 175 ==> y = 175 - x

0.3x + 0.65y = 96.25 ==> 0.3x + 0.65(175 - x) = 96.25

==> 0.3x + 113.75 - 0.65x = 96.25

==> 17.5 = 0.35x

==> x = 50 ==> y = 125

7 0

3 years ago