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3 years ago

Make an estimate. 4.9 x 3.1 Estimate:

Mathematics

2 answers:

Reil [10]3 years ago

6 0

Answer:

Step-by-step explanation:

5x3 =15

Reptile [31]3 years ago

5 0

Answer:

Step-by-step explanation:

We can round the two numbers so then we can multiply by the rounded numbers to get a close answer.

4.9 rounded to the nearest whole number is 5.

3.1 rounded to the nearest whole number is 3.

Now, we can multiply by the two numbers we got here.

5 × 3 = 15, so the answer to the question is 15.

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How do you factor this in the form (x+b)(x+c)

faust18 [17]

So you have your polynomial. To factor this out, you need to find the factors of -45 that will add up to 3. These two factors would be -5 and 8. So, you have factored your polynomial! (x-5)(x+8). If you are still unsure, simply use the FOIL method to check and see if you get the same polynomial back. Hope this helps!

7 0

3 years ago

Solve the following system of linear equations: 3x1+6x2+6x3 = -9 -2x1–3x2-3x3 = 3 If the system has infinitely many solutions, y

choli [55]

Answer:

The set of solutions is $\{\left[\begin{array}{c}x\\y\\z\end{array}\right]=\left[\begin{array}{c}12\\-7-r\\r\end{array}\right]: \text{r is a real number} \}$

Step-by-step explanation:

The augmented matrix of the system is $\left[\begin{array}{ccccc}3&6&6&-9\\-2&-3&-3&3\end{array}\right]$ .

We will use rows operations for find the echelon form of the matrix.

In row 2 we subtract $\frac{2}{3}$ from row 1. (R2- 2/3R1) and we obtain the matrix $\left[\begin{array}{cccc}3&6&6&-9\\0&1&1&-7\end{array}\right]$
We multiply the row 1 by $\frac{1}{3}$ .

Now we solve for the unknown variables:

$x_2+x_3=-7$ , $x_2=-7-x_3$
$x_1+2x_2+2x_3=-2$ , $x_1+2(-7-x_3)+2x_3=-2$ then $x_1=12$

The system has a free variable, the the system has infinite solutions and the set of solutions is $\{\left[\begin{array}{c}x\\y\\z\end{array}\right]=\left[\begin{array}{c}12\\-7-r\\r\end{array}\right]: \text{r is a real number} \}$

6 0

3 years ago

One positive number is the square of another positive number. their sum is 132. find the numbers.

Jet001 [13]

X +x²= 132
x +x²-132= 132-132
x²+x -132 = 0
(x-11) (x+12) = 0
x-11 = 0 X+12=0
x-11+11 = 0+11 X+12-12=0-12
x =11 x= -12

Check
x +x²= 132 x +x²= 132
-12 +-12²= 132 11 +11²= 132
-12 + 144 = 132 11+ 121=132
132= 132 132=132

Since the problem says positive the answer is (11,121)

8 0

3 years ago

Select the property of equality used to arrive at the conclusion<br> If x= 3, then x2 = 3x

Luda [366]

You used the fact that you can multiply both sides of an equality by the same, non-zero constant.

So, if you start with the trivial equality

$x=x$