Try breaking these into sections.
Twice: 2 times
The sum of: add
A number: choose a variable, like x
---Thus "the sum of a number and 4" becomes "add x and 4" which, mathematically, is "x+4"
-----Continuing to put it all together, "Twice the sum of a number and four" becomes "2 times (x+4)" which, mathematically, is "2(x+4)"
Is: equals
-------"Twice the sum of a number and four is" becomes "2(x+4)="
23 less than: subtract 23. This one tends to trick people; "23 less than" will become "__ - 23", NOT "23 - __"
three times the number: 3 times x
---"23 less than three times the number" becomes "subtract 23 from 3 times x" which, mathematically, is "3x-23"
-------So the final phrase: 2(x+4)=3x-23"
Answer:
Inflection points. It's where the second derivative of the function is equal to zero
Step-by-step explanation:
321 / 100 = 3.21 as you are dividing by 10, and then 10 again
Error// Error// Error// Error// Error// Error//
Answer:
y = -6
x = 1
Step-by-step explanation:
-x + 2y = -13
-x - 2y = 11
Sum the equations:
-x -x = -2x
+2y - 2y = 0
-13 + 11 = -2
then
-2x = -2
x = -2/-2
x = 1
from the first eq.
-x + 2y = -13
-1 + 2y = -13
2y = -13 + 1
2y = -12
y = -12/2
y = -6
check:
from the second eq.
-x -2y = 11
-1 -(2*-6) = 11
-1 -(-12) = 11
-1 + 12 = 11