Answer:
Step-by-step explanation:So we know x + y = 21 and 5x +10y = 165 We line them up in columns x + y = 21 5x +10y = 165 To eliminate the x variable, I'll multiply every element in the 1st equation by -5. -5x + -5y = -105 5x + 10y = 165 Now we combine (add) the equations, which eliminates x altogether. 5y = 60 ... y = 12 From there, x + 12 = 21 ... x = 21-12 ... x = 9 You should double check. Do 9 nickles and 12 dimes equal $1.65? A very important thing to remember using this method is to do the same thing to each element in the equation that you change! I hope that helps.
1. 6+ -35 = -29
2. -29+ 6 = -35
1. 37 + -33 = 4
2. -33 + 4 = 37
Answer:
1 hour=35+15=50
2 hours=35+15(2)=65
3 hours=35+15(3)=80
4 hours=35+15(4)=95
Step-by-step explanation:
For the first 1 X= 11 because all you need to do is add or subtract the numbers visible.
The second would be 2.
Answer:
1680 possible pizzas
Step-by-step explanation:
Pizza contains 2 different meat and 3 different vegetables.
If there are 5 meats and 8 vegetables, the customer can select any one of 3 types of crust.
Total number of ways to select meat = 5C2
nCr = n! /(n-r)! r!
5C2 = 5! / (5-2)!2!
= 5! / 3!2!
= 10
Total number of ways to select vegetables = 8C3
= 8!/(8-3)!3!
= 8! / 5!3!
= 56
Total number of pizza choice that can be made = 3 * 5C2 * 8C3
= 3*10*56
= 1680 possible pizza