Solve the top equation for x and then substitute that into the bottom equation and solve for y:
Top equation: subtract 4 from both sides to get x = y - 4
Substitution and simplify:
y = 4(y - 4) - 10
y = 4y - 16 - 10
y = 4y - 26
-3y = -26
y = 26/3 or 8 1/3 or 8.333 (those are all the same but in different forms)
Answer:
x = 5√2
y = 5√6
z = 5√3
ΔABC ~ ΔBDC ~ ΔADB
Step-by-step explanation:
ΔABC, ΔBDC, and ΔADB are all similar triangles to each other.
By definition of similar triangles, the corresponding sides have the same ratios.
CD from ΔBDC corresponds to BD from ΔADB, and BD from ΔBDC corresponds to AD from ΔADB. So:
CD / BD = BD / AD
10 / x = x / 5
x² = 50
x = 5√2
Since ΔBDC is right, we can use the Pythagorean Theorem to solve for y:
CD² + BD² = BC²
10² + (5√2)² = y²
y² = 100 + 50 = 150
y = 5√6
Again, since ΔΔABD is right, we can use the Pythagorean Theorem to solve for z:
AD² + BD² = AB²
5² + (5√2)² = z²
z² = 25 + 50 = 75
z = 5√3
False, you graph an open circle on -3 and shade to the right because x must be larger than -3 and it can not equal -3
Answer:
Step-by-step explanation:
2)
a) elimination method
b) substitution method
c) substitution method
For the first part we can elimate the y variable by subtracting the equations. We can then find the value of x.
For the second part we can substitute y as 2x+5 in the second equation and solve for x.
For the third part we can substitute y as 4x+3 in the first equation and solve for x.
3)
I prefer to use compatible numbers because by using this method it is easier to make a sum mentally. This is true because compatible numbers are close in value to the actual numbers. For a better understanding, let's take an example:
Suppose you have two numbers, namely 640 and 40. These two numbers are compatible for division because:
64 ÷ 4 = 16
So, we have used mental arithmetic to solve a more complex problem.
