Answer:

Step-by-step explanation:
1) slope-interception form is: y=s*x+i, where 's' and 'i' are slope and interception;
2) according to the condition s= -5/4, then the required equation is: y= -5/4 *x +i, where i - interception;
3) if to substitute (-4;7) into the required equation y= -5/4 *x +i, it is possible to calculate 'i':
7= -5/4*(-4)+i; ⇒i=2, then

Answer:
22
Step-by-step explanation:
mean is calculated as
mean = 
Given the mean of 12 numbers is 20 , then
= 20 ( multiply both sides by 12 )
sum = 240
Given the mean of 8 numbers is 25 , then
= 25 ( multiply both sides by 8 )
sum = 200
Total sum of the 20 numbers = 240 + 200 = 440, then mean of 20 numbers is
mean =
= 22
Answer:
x = 1
Step-by-step explanation:
To solve for a variable, you need to get the variable on one side of the equation, and by itself.
4x + 5 = x + 8
4x = x + 3 --- subtract 5 from both sides
3x = 3 --- subtract x from both sides
x = 1 --- divide both sides by 3
Answer:
17
Step-by-step explanation:
USING BIDMAS (Brackets Indices Division Multiplication Addition Subtraction)
6 − (9 − 2) + 3 × 6
9-2=7
3x6=18
6-7+18=17