x is the number of adults and y is the number of children.
x + y = 12
<span>14x + 10y = 140
lets multiply the first equation by -10 and then add it to the second equation:
-10x - 10y = -120
</span>14x + 10y = <span>140
</span>-----------------------
4x + 0 = 20
x = 20/4
x = 5
then substitute in the original equation:
x + y = <span>12
</span>5 + y = <span>12
</span>y = 12 - 5
y = 7
therefore there were 5 adults and 7 children
The exact value of sin (-270) is determined using the calculator in degrees mode. The answer is equal to 1. If the radians mode is used, -270 is equal to -2 pi/3. Hence using the calculator, we can verify that the answer is still 1. The value of -270 matters.
Answer:
the first one
Step-by-step explanation:
Since x can be any value, -infinity must be less than x because you can always subtract 1 from x. Also, infinity must be more than x because you can always add 1 to x.
Answer:
(10, 3)
Step-by-step explanation:
Solve by Substitution
2x − 4y = 8 and 7x − 3y = 61
Solve for x in the first equation.
x = 4 + 2y 7x − 3y = 61
Replace all occurrences of x with 4 + 2y in each e quation.
Replace all occurrences of x in 7x − 3y = 61 with 4 + 2y. 7 (4 + 2y) − 3y = 61
x = 4 + 2y
Simplify 7 (4 + 2y) − 3y.
28 + 11y = 61
x = 4 + 2y
Solve for y in the first equation.
Move all terms not containing y to the right side of the equation.
11y = 33
x = 4 + 2y
Divide each term by 11 and simplify.
y = 3
x = 4 + 2y
Replace all occurrences of y with 3 in each equation.
Replace all occurrences of y in x = 4 + 2y with 3. x = 4 + 2 (3)
y = 3
Simplify 4 + 2 (3).
x = 10
y = 3
The solution to the system is the complete set of ordered pairs that are valid solutions.
(10, 3)
The result can be shown in multiple forms.
Point Form:
(10, 3)
Equation Form:
x = 10, y = 3
Answer:
Step-by-step explanation:
Ecosystems form in response to the unique but predictable climate of each geographic area. And since elevation and topography affect climate, ecosystems are different at different elevations. The life in any given ecosystem is the direct result of elevation, topography, and temperature, and rainfall patterns.
