All categories

3 years ago

Simplify the expression 3a + b, when a=1.4 -2x and b=-0.2x + 1.7*

Mathematics

2 answers:

Aleksandr-060686 [28]3 years ago

7 0

Answer:

Step-by-step explanation:

3a + b

a = 1.4 - 2x

b = -0.2x + 1.7

3 ( 1.4 - 2x ) + -0.2x + 1.7

= 4.2 - 6x - 0.2x + 1.7

= 4.2 + 1.7 - 6x - 0.2x ( by rearranging the like terms )

= <u><em>5.9 - 6.2 x</em></u>

hope this helps

plz mark as brainliest!!!!!!!!

kenny6666 [7]3 years ago

3 0

Answer:5.9-6.2x

Step-by-step explanation:

a=1.4-2x

b=-0.2x+1.7

3a+b

=3(1.4-2x)+(-0.2x+1.7)

=4.2-6x-0.2x+1.7

=4.2+1.7-6x-0.2x

=5.9-6.2x

You might be interested in

You are attempting to estimate the number of protester marching through the city

Alenkinab [10]

9514 1404 393

Answer:

1000

Step-by-step explanation:

If the number of protesters per minute remains a constant, then you could write the proportion ...

p/12 = 177/2.1

Multiplying by 12 gives ...

p = 12(177/2.1) ≈ 1011.4

Here, minutes are given to 2 significant figures, and the initial count is given to 3 significant figures. The best you can hope for is that your estimate is good to 3 significant figures:

1010 protesters

It is probably sufficient to report the number to 2 significant figures*:

1000 protesters

_____

* Unfortunately, with a number like 1000, the only way you can tell it has 2 significant figures is to report it as 1.0×10³ or 10. hundreds. The trailing zeros are usually not considered significant.

3 0

3 years ago

find the centre and radius of the following Cycles 9 x square + 9 y square +27 x + 12 y + 19 equals 0

Citrus2011 [14]

Answer:

Radius: $r =\frac{\sqrt {21}}{6}$

$Center = (-\frac{3}{2}, -\frac{2}{3})$

Step-by-step explanation:

Given

$9x^2 + 9y^2 + 27x + 12y + 19 = 0$

Solving (a): The radius of the circle

First, we express the equation as:

$(x - h)^2 + (y - k)^2 = r^2$

Where

$r = radius$

$(h,k) =center$

So, we have:

$9x^2 + 9y^2 + 27x + 12y + 19 = 0$

Divide through by 9

$x^2 + y^2 + 3x + \frac{12}{9}y + \frac{19}{9} = 0$

Rewrite as:

$x^2 + 3x + y^2+ \frac{12}{9}y =- \frac{19}{9}$

Group the expression into 2

$[x^2 + 3x] + [y^2+ \frac{12}{9}y] =- \frac{19}{9}$

$[x^2 + 3x] + [y^2+ \frac{4}{3}y] =- \frac{19}{9}$

Next, we complete the square on each group.

For $[x^2 + 3x]$

1: Divide the $coefficient\ of\ x\ by\ 2$

2: Take the $square\ of\ the\ division$

3: Add this $square\ to\ both\ sides\ of\ the\ equation.$

So, we have:

$[x^2 + 3x] + [y^2+ \frac{4}{3}y] =- \frac{19}{9}$

$[x^2 + 3x + (\frac{3}{2})^2] + [y^2+ \frac{4}{3}y] =- \frac{19}{9}+ (\frac{3}{2})^2$

Factorize

$[x + \frac{3}{2}]^2+ [y^2+ \frac{4}{3}y] =- \frac{19}{9}+ (\frac{3}{2})^2$

Apply the same to y

$[x + \frac{3}{2}]^2+ [y^2+ \frac{4}{3}y +(\frac{4}{6})^2 ] =- \frac{19}{9}+ (\frac{3}{2})^2 +(\frac{4}{6})^2$

$[x + \frac{3}{2}]^2+ [y +\frac{4}{6}]^2 =- \frac{19}{9}+ (\frac{3}{2})^2 +(\frac{4}{6})^2$

$[x + \frac{3}{2}]^2+ [y +\frac{4}{6}]^2 =- \frac{19}{9}+ \frac{9}{4} +\frac{16}{36}$

Add the fractions

$[x + \frac{3}{2}]^2+ [y +\frac{4}{6}]^2 =\frac{-19 * 4 + 9 * 9 + 16 * 1}{36}$

$[x + \frac{3}{2}]^2+ [y +\frac{4}{6}]^2 =\frac{21}{36}$

$[x + \frac{3}{2}]^2+ [y +\frac{4}{6}]^2 =\frac{7}{12}$

$[x + \frac{3}{2}]^2+ [y +\frac{2}{3}]^2 =\frac{7}{12}$

Recall that:

$(x - h)^2 + (y - k)^2 = r^2$

By comparison:

$r^2 =\frac{7}{12}$

Take square roots of both sides

$r =\sqrt{\frac{7}{12}}$

Split

$r =\frac{\sqrt 7}{\sqrt 12}$

Rationalize

$r =\frac{\sqrt 7*\sqrt 12}{\sqrt 12*\sqrt 12}$

$r =\frac{\sqrt {84}}{12}$

$r =\frac{\sqrt {4*21}}{12}$

$r =\frac{2\sqrt {21}}{12}$

$r =\frac{\sqrt {21}}{6}$

Solving (b): The center

Recall that:

$(x - h)^2 + (y - k)^2 = r^2$

Where

$r = radius$

$(h,k) =center$

From:

$[x + \frac{3}{2}]^2+ [y +\frac{2}{3}]^2 =\frac{7}{12}$

$-h = \frac{3}{2}$ and $-k = \frac{2}{3}$

Solve for h and k

$h = -\frac{3}{2}$ and $k = -\frac{2}{3}$

Hence, the center is:

$Center = (-\frac{3}{2}, -\frac{2}{3})$

6 0

2 years ago

Q is the midpoint of GH¯¯¯¯¯¯ , GQ=2x+3, and GH=5x−5 . What is the length of GQ¯¯¯¯¯ ?

trasher [3.6K]

The length of GQ is 2 1/3 (two and one-third) where x equals -2/3 (negative two-thirds).

4 0

3 years ago

Grapes cost $3.25 per pound. Darius paid a total of $26 for grapes.

Dmitry [639]

Answer:He buys 8 pounds

Step-by-step explanation:

You can either just add up the $3.25 until you get to the end-price, but that wont always work for every problem. The best way is to divide the 26 with the 3.25 in a written devision.

4 0

3 years ago

Read 2 more answers

A band expects to put 12 songs on their next CD. The band writes and records 25% more songs than they expect to put on the CD.

sweet-ann [11.9K]

12 songs. 25% of 12 is 3, so you add 3 to 12 and get 15. You then find that 20% of 15 is 3 so you subtract 3 from 15 and get 12 again.

7 0

3 years ago

Read 2 more answers