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3 years ago

Find a1 and d for an arithmetic sequence with these terms. a3=-8 and a7=32

1 answer:

4 0

We know that
the formula for the <span>arithmetic sequence is
</span><span>an = a1 + (n - 1)*d
where
a1 is the first term
n is the numbers of terms

for n=3 a3=-8
-8=a1+(3-1)*d-----> -8=a1+2*d-----> equation 1

for n=7 a7=32
-32=a1+(7-1)*d----> -32=a1+6*d----> equation 2

multiply equation 2 by -1-----> 32=-a1-6*d------> equation 3

add equation 1 and equation 3
</span>-8=a1+2*d
32=-a1-6*d
----------------
24=-4*d------> d=-6
-8=a1+2*(-6) (substitute the value of d in equation 1)
-8=a1-12-----> a1=-8+12-----> a1=4

the answer is
a1=4
d=-6

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Alex is 1.6 m tall and Noah is 1.5 times as tall as Alex. How much tall is Noah in centimeters?

Yanka [14]

D= difference in height

A= Alex's height (1.6m) N= Noah's height (1.5A)

Step 1:

D=N-A

substitute N= 1.5 A in for N

D= 1.5(1.6) - 1.6

D= 2.4 - 1.6

D= 0.8 m difference in height

Step 2:

Convert meters to centimeters 1 m = 100 centimeters

0.8 x 100-80cm

Noah is 80cm taller than Alex.

Hope this helps! :)

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2 years ago

Please only answer if you know the correct answer! Will give brainliest and points!

Mandarinka [93]

Step-by-step explanation:

845/1160 = 0.728

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42.25/58 = 0.728

23.4/29 = 0.806

16.9/23.2 = 0.728

25.35/34.8 = 0.728

Hence the 2nd, 4th and 5th options are correct.

7 0

3 years ago

Read 2 more answers

Pls help sixowiskosixo

erma4kov [3.2K]

The given question is a quadratic equation and we can use several methods to get the solutions to this question. The solution to the equation are 3/4 and -5/6 and the greater of the two solutions is 3/4

<h3>Quadratic Equation</h3>

Quadratic equation are polynomials with a second degree as it's highest power.

An example of a quadratic equation is

$y = ax^2 + bx + c$

The given quadratic equation is $24x^2 + 2x = 15$

Let's rearrange the equation

$24x^2 + 2x = 15\\24x^2 + 2x - 15 = 0$

This implies that

a = 24
b = 2
c = -15

The equation or formula of quadratic formula is given as

$y = \frac{-b +- \sqrt{b^2 - 4ac} }{2a}$

We can substitute the values into the equation and solve

$y = \frac{-b +- \sqrt{b^2 - 4ac} }{2a}\\y = \frac{-2 +- \sqrt{2^2 -4 * 24 * (-15)} }{2*24} \\y = \frac{-2+-\sqrt{4+1440} }{48} \\y = \frac{-2+-\sqrt{1444} }{48} \\y = \frac{-2+- 38}{48} \\y = \frac{-2+38}{48} \\y = \frac{3}{4}\\ \\or\\y = \frac{-2-38}{48} \\y = \frac{-40}{48} \\y = -\frac{5}{6}$

From the calculations above, the solution to the equation are 3/4 and -5/6 and the greater of the two solutions is 3/4

Learn more on quadratic equation here;

brainly.com/question/8649555

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1 year ago

Write the equation for a line perpendicular to y=-3x+18 that goes through the point (-12,6)

Hatshy [7]

Answer:

$y=\frac{1}{3} x -14$

Step-by-step explanation:

The equation of the line you will find should be in the form y =mx+c , where m is the gradient and c is the y intercept.

The gradient of a line that is perpendicular to a line [of a known gradient] is the negative reciprocal of the gradient of the first. i.e. if a is the known gradient and the perpendicular gradient is b, ab = -1. Therefore the -3b=-1 and b= 1/3

you can now write y = mx +c as y = 1/3x +c

As you have been given a coordinate, you can input these values into y= 1/3x + c

-12 = 1/3(6) +c

-12 - 2 = c

c = -14

hence the equation of the line is y= 1/3x -14

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2 years ago

Izzie thinks of a number

Rama09 [41]

I believe the number is 406,152

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2 years ago

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