What if I wrote + 38 - 28 .
Would you be able to solve it that way ?
They're both the same number.
Its an Integer. Integers include negative numbers, zero and positive numbers :)
18 kg of 15% copper and 72 kg of 60% copper should be combined by the metalworker to create 90 kg of 51% copper alloy.
<u>Step-by-step explanation:</u>
Let x = kg of 15% copper alloy
Let y = kg of 60% copper alloy
Since we need to create 90 kg of alloy we know:
x + y = 90
51% of 90 kg = 45.9 kg of copper
So we're interested in creating 45.9 kg of copper
We need some amount of 15% copper and some amount of 60% copper to create 45.9 kg of copper:
0.15x + 0.60y = 45.9
but
x + y = 90
x= 90 - y
substituting that value in for x
0.15(90 - y) + 0.60y = 45.9
13.5 - 0.15y + 0.60y = 45.9
0.45y = 32.4
y = 72
Substituting this y value to solve for x gives:
x + y = 90
x= 90-72
x=18
Therefore, in order to create 90kg of 51% alloy, we'd need 18 kg of 15% copper and 72 kg of 60% copper.
Answer:
14^3/100 i think im not 100% sure so if its wrong dont get mad
Step-by-step explanation:
Given: ∠JNL and ∠MNK are vertical angles and m∠MNK=90°
Prove: ∠JNL is a right angle.
Statements Reasons
1. ∠JNL and ∠MNK are vertical angles. Given
2. 
Vertical angle theorem
3. 
Angle congruence postulate
4. 
Given
5. 
<u> Substitution Property of Equality</u>
Since, the measures of angle JNL and MNK are equal and the measure of angle MNK is 90 degrees. therefore, by substitution property of equality, both the angles JNL and MNK will have an equal measure.
Therefore,
6. ∠JNL is a right angle. Definition of right angle
