1) Rational because the square root of 16 is 4 and 4 times 4/7 is a rational number (16/7)
2) Irrational because square root of 684 is irrational C
3) The square root of a is irrational so the answer is irrational. The square root of c is rational so the answer is rational.
4) Jacob is wrong because the square root of 5/7 is irrational so the answer to the problem is irrational.
Answer:
5.0E + 12
Step-by-step explanation:
I don't do conversions but i tried my best to help
Answer:
20kg of 25% copper alloy
30kg of 60% copper alloy
Step-by-step explanation:
There are 2 kinds of metal, first metal(A) have 25% copper while the second metal(B) has 60% copper. The metalworker want to create 50kg of metal, which means the total weight of both metals is 50kg (A+B = 50). The metalworker also want the metal made of a 46% which is 23kg(0.25A + 0.6B = 0.46*50). From these sentences, we can derive 2 equations. We can solve this with substitution.
A+B = 50
A= 50-B
Let's put the first equation into the second.
0.25A + 0.6B = 0.46 *50
0.25(50-B) + 0.6B =23
12.5 - 0.25B + 0.6B =23
0.35B=23 -12.5
B= 10.5/ 0.35= 30
Then we can solve A
A= 50-B
A= 50-30
A=20
Step-by-step explanation:
(- 4xy - 2) - 5(xy - 2) - 1
-4xy - 2 - 5xy + 10 - 1
Solving like terms
-9xy + 7