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3 years ago

Find the value of 2a squared + 5b squared when a = -6 and b =2

Mathematics

1 answer:

jenyasd209 [6]3 years ago

5 0

given 2a² + 5b²

substitute given values for a and b into the expression

2(- 6)² + 5(2)² = (2 × 36 ) + (5 × 4) = 72 + 20 = 92

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Plz help ...........

bogdanovich [222]

Step-by-step explanation:

Given c = longest of triange = 15m

Given b = short side of triangle = 9m

By pythagoras' Theorem,

${c}^{2} = {a}^{2} + {b}^{2} \\ {a}^{2} + {b}^{2} = {c}^{2} \\ {a}^{2} + {(9)}^{2} = {(15)}^{2} \\ {a}^{2} + 81 = 225 \\ {a}^{2} = 225 - 81 \\ {a}^{2} = 144 \\ a = \sqrt{144} \\ = 12m$

6 0

3 years ago

Solve 2x+y=3 x+y=5 in substitution method

Nastasia [14]

2x+y=3
- x+y=5
---------------
x=-2

2(-2)+y=3
y=7

-2+y=5
y=7

(-2,7)

4 0

3 years ago

What's the difference between adding two rational number and get a negative number

nikklg [1K]

Comparing two rational numbers

Use fraction form:

Make the denominators the same and compare the numerators. The number with the smaller numerator is smaller. For example, to compare a/b and c/d, we rewrite

a/b=a*d/b*d

= ad/bd and c/d = c*b/d*b=bc/bd

Now just compare the numerators : "ad" and "bc"

Multiplying and Dividing Rational Numbers

Multiplying and dividing rational numbers in decimal form is the same as multiplying and dividing integers. The decimal place of the product is the same of all decimals of all multiplied numbers. For example, 3.12*2.4.

Solution => 3.12*2.4=7.488

When multiplying or dividing rational numbers in fractional form, you multiply the numerators (N*N) and then multiply the denominators (D*D).

When dividing rational numbers in fractional form, first take the reciprocal of the divisor, and then multiply the numerators and the denominators.

Example => 5/9 divided by 2/7 .

Solution => 5/9 * 7/2 = 35/18

Adding Rational numbers

Adding and Subtracting rational numbers in decimal form is the same as adding and subtracting integers.

Example => -3.54+2.79=-0.75

When adding or subtracting rational numbers in fractional form, first make the denominator equal, and then add or subtract the numerators.

6 0

3 years ago

Which two numbers have a mean of 10 and a range of 4

Elden [556K]

Answer:

12 and 8

Step-by-step explanation:

set two numbers as x and y

mean of 10 → x+y/2=10

range of 4 → x-y=4

x+y=20

+ x-y=4

____________

2x=24, x=12

12-y=4, y=8

6 0

3 years ago

Find the length of the segment that joins the points (-5, 4) and (6,-3).

Helen [10]

Answer:

$\boxed {\boxed {\sf d=\sqrt{170} \ or \ d\approx 13.04}}}$

Step-by-step explanation:

We are asked to find the length of a segment or the distance between the 2 points. The formula for distance is:

$d= \sqrt{(x_2-x_1)^2+(y_2-y_1)^2$

where (x₁ y₁) and (x₂, y₂) are the points. We are given the points ( -5, 4) and (6, -3). If we match the number and the corresponding variable, it is:

x₁= -5
y₁= 4
x₂= 6
y₂ = -3

Substitute the values into the formula.

$d= \sqrt{(6--5)^2+(-3-4)^2$

Solve inside the parentheses.

6--5 (Back to back negative signs become a positive)= 6+5 =11
-3-4= -7

$d= \sqrt{(11)^2+(-7)^2$

Solve the exponents.

(11)²= 11*11= 121
(-7)²= -7*-7= 49

$d= \sqrt {(121)+(49)$

Add.

$d= \sqrt {170}$

$d=13.0384048104$

Even though it's not specified, we could round to the nearest hundredth to make the answer more concise. The 8 in the thousandth place tells us to round the 3 to a 4 in the hundredth place.

13.0384048104

$d\approx 13.04$

The length of the segment is √170 or approximately 13.04.

7 0

3 years ago