Answer:
x = 5.75
Step-by-step explanation:
4^(x+7) = 8^(2x-3)
But; 4^(x+7) = 2^2(x+7)
8^(2x-3) = 2^3(2x-3)
2^2(x+7) = 2^3(2x-3)
Since the bases are the same;
2(x+7) = 3(2x-3)
2x + 14 = 6x -9
14 + 9 = 6x - 2x
23 = 4x
x = 23/4
<u>x = 5.75</u>
We need to use the variables m and n to represent both numbers.
Their sum must equal -15. Therefore, we can write the next equation:
m + n = -15
If one number is five less than the other, we need to choose one variable and then we can write it in terms of the other variable. Then:
n = m-5
To find the value for each number, we can replace the n equation on the first equation:
m + n = -15
m + (m-5)= -15
Then:
m + m - 5 = -15
2m -5 = -15
Solve the equation for m:
Add both sides 5 units:
2m - 5 +5 = -15+5
2m = -10
Divide both sides by 2:
2m/2 = -10/2
m = -5
Finally, replace the m value on the first equation:
m + n = -15
-5 + n = -15
Then, solve the equation for n:
Add both sides by 5:
-5+5 + n = -15 +5
n = -10
Hence, both numbers are m=-5 and n= -10.
The equations separated by a comma are m + n = -15,n = m-5.
The numbers separated by a comma are -5,-10.
Answer:
The entire area of the sailboat is 60cm²
Step-by-step explanation:
You can find the area of this shape by breaking it down into simpler shapes and adding up their individual areas.
In this case, the areas we'll use are the rectangle at the bottom, and the pair of triangles at the top.
Because the two triangles can be put together to form a single triangle, we don't need to measure them independently. We can simply take the total length of their bases, multiply it by their height, and divide by two. This follows the rule that the area of a triangle is equal to the area of the square that contains it divided by two.
(2cm + 3cm) × 6cm
= 5cm × 6cm
= 30cm²
The rectangle's area is of course equal to its width times its height, so we can say:
2.5cm × 12cm
= 30cm²
The total area of the shapes then is 30cm² + 30 cm², giving us a total area of 60cm²
Answer:
B
Step-by-step explanation:
$5.20 is about $5.00, 21 is about 20, so $5.00 * 20 *4 = $400.
Checking this: $5.20 * 21 * 4 = $436.80