Ask question

Ask question

All categories

3 years ago

6

Factorise: a squared +8a -20

1 answer:

Vaselesa [24]3 years ago

8 0

Factor out the 4 in both equations
8a^2-20^2=(2^2 times a^2 times 2)-(2^2 times 5)
therefor it is also equal to
(2a)^2 times 2-(2^2 times 5)
we can force it into a difference of 2 perfect squares which is a^2-b^2=(a-b)(a+b)
(2a√2)^2-(2√5)^2=((2a√2)-(2√5))((2a√2)+(2√5))

You might be interested in

If a line has a slope of 2 and contains the point (-2,1), what is its equation in point-slope form?

kondaur [170]

The equation for slope is y=mx+b. slope is m. 2 is the slope. so you know the m part of the equation is 2. just by eliminating the answers that don’t have 2 as the slope, A is your answer.

5 0

3 years ago

Simplify the expression. 6 + (14 – 6) • 3 + 2 • 3 PLZ HELP

LiRa [457]

Your answer will be 8

3 0

3 years ago

Read 2 more answers

Mark drew two triangles and 8 arrows as part of a set of 13 shapes. The only other type of shape in the set is a circle. What fr

luda_lava [24]

Answer:

3/13

Step-by-step explanation:

First...

What we know

1. There is a set of 13 shapes.

2. With 2 triangles, 8 arrows, and circles.

Next...

Take the number of triangles and arrows and add them up.

2 + 8 = 10

Finally...

Convert it into the fraction 10/13 and subtract it by the total 13/13.

This results 3/13.

3 0

3 years ago

A man invests $2000 in an account that pays 6.5% interest per year, compounded quarterly.

skelet666 [1.2K]

Answer:

The correct answer is a. $2275.28; b. 17.04 years

Step-by-step explanation:

Principal to be invested is $2000

Interest rate (r) per year is 6.5 quarterly.

Interest is calculated compoundly.

a. Time (t) for the investment is given to be 2 years.

Amount after two years is = Principal × $( 1+ \frac{r}{100n}) ^ {nt}$ where the value of n is 4.

⇒ A = 2000 × $( 1+ \frac{6.5}{400}) ^ {8}$

⇒ A = $2275.28.

b. Now the value of A is given to be triple the principal = $ (3 × 2000).

Therefore we need to find the value of t.

⇒ 3 × 2000 = 2000 × $( 1+ \frac{6.5}{400}) ^ {4t}$

⇒ ㏑ 3 = 4t × ㏑ ( 1.01625)

⇒ t = 17.04

Therefore it would take 17.04 years for the principal to triple.

5 0

3 years ago

Compute each sum below. If applicable, write your answer as a fraction.

Alex777 [14]

Answer:

First equation is -425

Second equation is 11.25

Step-by-step explanation:

First equation we can write as

$\sum_{i=0}^7 5 \times (-2)^i$

computing

When i=0 -> $5 \times (-2)^0 =5$

When i=1 -> $5 \times (-2)^1 = -10$

...

When i=7 -> $5 \times (-2)^7 = --640$

then replacing each term we have

$5 + (-10) + ( 20) + ( -40) + (80) +( -160) + 320 + (-640) = -425$

For the second equation we'll have 9 terms, solving in a similar fashion

When i=1 -> $\frac{1}{4}1=0.25$

When i=2 -> $\frac{1}{4}2=0.50$

When i=3 -> $\frac{1}{4}3=0.75$

...

When i=9 -> $\frac{1}{4}9=2.25$

So we have 0.25 + 0.50 + 0.75 + 1.00 + 1.25 + 1.50+ 1.75 +2.00 +2.25

4 0

3 years ago