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1 year ago

100 Points!!!

Mathematics

2 answers:

Mars2501 [29]1 year ago

7 0

Let's see

Take 28

(28)²
(30-2)²
30²-2(30)(2)+2²
900-120+4
780+4
784

Take 9,10

9³+10³
(9+10)(9²-9×10+10²)
(19)(81-90+100)
19(181-90)
19(91)
1729

oee [108]1 year ago

4 0

Answer:

Two-digit number greater than 25: 32

Rewrite 32 as the difference of 2 numbers: 40 - 8

Therefore, x = 40 and y = 8

$\begin{aligned}\implies (40-8)^2 & =40^2-2(40)(8)+8^2\\ & = (4 \cdot 10)^2-(80)(8)+64\\ & = 4^2 \cdot 10^2-640+64\\ & = 16 \cdot 100-640+64\\ & = 1600-640+64\\ & = 960+64\\ & = 1024\end{aligned}$

Let a = 10

Let b = 11

$\begin{aligned}\implies 10^3+11^3 & =(10+11)(10^2-10 \cdot 11+11^2)\\& = 21(100-110+121)\\ & = 21(-10+121)\\ & = 21(111)\\& = 21 (100 + 10 + 1)\\ & = (21 \cdot 100)+(21 \cdot 10)+(21 \cdot 1)\\ & = 2100 +210+21\\ & = 2310 + 21\\ & = 2331\end{aligned}$

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Charlie saves $22.25 each month for 6 months. In the seventh month, he only saves $10.30. How much money will Charlie have saved

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Charlie would save $143.8 after 7 months.

5 0

2 years ago

Read 2 more answers

4/10x - 2x + 8/5 = 4/5

mamaluj [8]

$\large\displaystyle\text{$\begin{gathered}\sf \left(\frac{4}{10}\times x\right)-(2 \times x)+\frac{8}{5}=\frac{4}{5} \end{gathered}$}$

Reduce the fraction 4/10, to its minimum expression, extracting and canceling 2.

$\large\displaystyle\text{$\begin{gathered}\sf \frac{2}{5}x-2x+\frac{8}{5}=\frac{4}{5} \end{gathered}$}$

Combine $\bf{\frac{2}{5}x }$ and -2x to get $\bf{-\frac{8}{5}x}$ .

$\large\displaystyle\text{$\begin{gathered}\sf -\frac{8}{5}x+\frac{8}{5}=\frac{4}{5} \ \end{gathered}$}$

Subtract 8/5 from both sides.

$\large\displaystyle\text{$\begin{gathered}\sf -\frac{8}{5}x=\frac{4}{5}-\frac{8}{5} \ \ \end{gathered}$}$

Since 4/5 and 5/8 have the same denominator, join their numerators to subtract them.

$\large\displaystyle\text{$\begin{gathered}\sf -\frac{8}{5}x=\frac{4-8}{5} \end{gathered}$}$

Subtract 8 from 4 to get -4.

$\large\displaystyle\text{$\begin{gathered}\sf -\frac{8}{5}x=-\frac{4}{5} \end{gathered}$}$

Multiply both sides by $\bf{-\frac{5}{8}}$ , the reciprocal of $\bf{-\frac{5}{8}}$ .

$\large\displaystyle\text{$\begin{gathered}\sf x=-\frac{4}{5}\left(-\frac{5}{8}\right) \end{gathered}$}$

Multiply -4/5 by -5/8 (to do this, multiply the numerator by the numerator and the denominator by the denominator).

$\large\displaystyle\text{$\begin{gathered}\sf x=\frac{-4(-5)}{5\times8} \ \to \ \ Multiply \end{gathered}$}$
$\large\displaystyle\text{$\begin{gathered}\sf x=\frac{20}{40} \end{gathered}$}$