Answer:
x^2 + 5x - 84 = 0
x = 7
Step-by-step explanation:
let the sister's age = y
sister's age (y) = 5 + x equation 1
xy = 84 equation 2
Make y the subject of the formula in equation 2
y = 84/x
equate equation 1 and 2
84/x = 5 + x equation 3
Multiply equation 3 by x
84 = 5x + x^2
x^2 + 5x - 84 = 0
tjis can be solved using quadratic equation
x^2 -7x + 12x -84 = 0
x(x + 12) -7(x + 12)
x = 7 or - 12
age cant be negative so his age is 7
Step-by-step explanation:
the one is the middle top the one in the middle bottom and the one in the bottom right
The product of 2 and 3 is 6. When you take away, or subtract, 5 from 6, you get 1.
Answer:
a. Domain: (-∞, ∞)
Range: (0,∞)
b. Domain: (-∞, ∞)
Range: (0,∞)
c. Domain: (-∞, ∞)
Range: (-∞,0)
d. Domain: (-∞, ∞)
Range: (-∞,0)
e. Domain: (-∞, ∞)
Range: (0,∞)
Step-by-step explanation:

These equations are all exponential functions. Exponential functions are curves which approach a horizontal asymptote usually at y=0 or the x-axis unless a value has been added to it. If it has, the curve shifts. None of these have that and their y - values remain between 0 and ∞. This is the range, the set of y values.
However, the range of exponentials can change based on the leading coefficient. If it is negative the graph flips upside down and its range goes to -∞. C and D have this. Their range is (-∞, 0)
In exponential functions, the x values are usually not affected and all are included in the function. Their domain is (-∞, ∞). All of these equations have this domain.
a. Domain: (-∞, ∞)
Range: (0,∞)
b. Domain: (-∞, ∞)
Range: (0,∞)
c. Domain: (-∞, ∞)
Range: (-∞,0)
d. Domain: (-∞, ∞)
Range: (-∞,0)
e. Domain: (-∞, ∞)
Range: (0,∞)
Answer:
60 degrees
Step-by-step explanation:
angle y is vertically opposite to angle a, (we can call it.)
angle x is supplementary to the other angle inside the triangle, which we can call angle b.
so, angle a is 60 degrees, as vertically opposite angles are equal
angle b is 60 degrees as supplementary angles = 180
based of the sum of angles in a triangle is 180 theorem;
60+60+unknown= 180
so unknown is 60 degrees