All categories

3 years ago

What is the answer to -2a-9=6a+15

Mathematics

2 answers:

statuscvo [17]3 years ago

6 0

Answer:

a=-3

Step-by-step explanation:

-2a-9=6a+15

+2a +2a

-9=8a+15

-15 -15

-24=8a

8 8

-3=a

timurjin [86]3 years ago

4 0

Answer:

$a=-3$

Step-by-step explanation:

$-2a-9=6a+15$

Add 9 to both sides:

$-2a-9+9=6a+15+9$

$-2a=6a+24$

Subtract 6a from both sides:

$-2a-6a=6a+24-6a$

$-8a=24$

Divide both sides by -8:

$\frac{-8a}{-8}=\frac{24}{-8}$

$a=-3$

You might be interested in

PLEASE HELP I REALLY NEED IT NOW!!!...

Serggg [28]

Answer:136°

Step-by-step explanation:

4 0

3 years ago

Slope intercept form -6×+3y=9

Mars2501 [29]

Answer:

m=-3 b=6

Step-by-step explanation:

3y= -6x + 9

divide everything by 3

y=-3x+6

m=-3 b=6

4 0

4 years ago

Read 2 more answers

Three boys cut out hundredths decimal models. Luke shades three fourths of one model. Owen shades four small squares of one mode

Ad libitum [116K]

Answer:

Luke = 0.75

Owen = 0.04

Jacob = 2.9

Step-by-step explanation:

A model = 100 small squares

100 small squares = 1

Luke shades three fourths of one model.

Luke = 3/4 of 1 model

= 3/4 × 1

= 0.75

Owen shades four small squares of one model.

Owen = 4/100

= 0.04

Jacob shades two full models and nine tenths of another model

Jacob = 2 + 9/10

= 2 + 0.9

= 2.9

Luke = 0.75

Owen = 0.04

Jacob = 2.9

6 0

3 years ago

70 POINTSS!!!! URGETT PLS HELP!! Vectors t = −5i + 2j, u = −3i + 7j, and v = 8i + 20j are given.

LUCKY_DIMON [66]

The angle between the vectors t and u is 45°. And the vector t and vector w are orthogonal to each other.

<h3>What is a vector?</h3>

The quantity which has magnitude, direction and follows the law of vector addition is called a vector.

The vectors are given below.

t = −5i + 2j, u = −3i + 7j, and v = 8i + 20j

Part A: Then the angle between vectors t and u will be

$\cos \theta = \dfrac{\overrightarrow{a} \cdot \overrightarrow{b}}{|\overrightarrow{a}| + |\overrightarrow{b}|}$

Then we have

cos θ = [(−5i + 2j)(−3i + 7j)] / [√{(-5²) + 2²} + √{(-3)² + 7²}]

cos θ = 1 / √2

θ = 45°

Part B: c is a scalar

If $\rm \overrightarrow{\rm v} = (a, b)$ , then $\rm c\overrightarrow{\rm v} = c(ca, cb)$

Let c = 2, then we have

$\overrightarrow{\rm w} = c\overrightarrow{v}\\\\\overrightarrow{\rm w} = (2*8, 2*20)\\\\\overrightarrow{\rm w} = (16, 40)$

Part C: Use the dot product to determine if t and w are parallel or orthogonal.

$\overrightarrow{\rm t} \cdot \overrightarrow{\rm w} = (-5, 2)(16, 40)\\\\ \overrightarrow{\rm t} \cdot \overrightarrow{\rm w} = -5*16+ 2*40\\\\ \overrightarrow{\rm t} \cdot \overrightarrow{\rm w} = -80+ 80\\\\ \overrightarrow{\rm t} \cdot \overrightarrow{\rm w} = 0$