Answer:
=900
Step-by-step explanation:
.The children
initially didn't expect to have fun cleaning the
attic, but then they discovered the treasure
map.
Answer:
x = 7 and y = −2
(7, -2)
Step-by-step explanation:
x = 1 - 3y
3x + 3y = 15
Substitute −3y + 1 for x in 3x + 3y = 15:
3(1 - 3y) + 3y = 15
3 - 9y + 3y = 15
3 - 6y = 15
-3 -3
-6y = 12
/-6 /-6
y = -2
Now we solve for x. Substitute −2 for y in x = −3y + 1:
x = 1 - 3y
x = 1 + (-3)(-2)
x = 1 + 6
x = 7
Now we check our solution.
x = 1 - 3y
7 = 1 + (-3)(-2)
7 = 7 ✅
3x + 3y = 15
3(7) + 3(-2) = 15
21 - 6 = 15
15 = 15 ✅
If two secants are drawn from a point lying outside a circle, then the product of one secant on its outer part is equal to the product of the other secant on its outer part.
DE*CE = AE*BE
DE = CD + CE = 1 + x + 4 = x + 5
AE = AB + BE = 11 + x + 1 = x + 12
(x+5)(x+4)=(x+12)(x+1)
x² + 4x + 5x + 20 = x² + x + 12x + 12
9x + 20 = 13x + 12
20 - 12 = 13x - 9x
8 = 4x
x = 8/4
x = 2
Answer: In mathematics, a variable is a symbol which functions as a placeholder for varying expression or quantities, and is often used to represent an arbitrary element of a set. In addition to numbers, variables are commonly used to represent vectors, matrices and functions
Step-by-step explanation:A symbol for a value we don't know yet. It is usually a letter like x or y.
Example: in x + 2 = 6, x is the variable.
Why "variable" when it may have just one value? In the case of x + 2 = 6 we can solve it to find that x = 4. But in something like y = x + 2 (a linear equation) x can have many values. In general it is much easier to always call it a variable even though in some cases it is a single value.