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.
I will but the picture is blurry
Combine place value strategy is useful if you try to subtract a number with bigger digits from a number with a smaller digit in the same place... such as now, where 3 is smaller than 9 in the ones place.
Then we can combine two place values: 23 and 19 and subtruct those. 23-19 is 4 (you can just count up from 19 to 23), so you know that the two will give the result of 04, and then you can proceed to the left: 2-1=1.
so the final result will 104.
You want to follow PEMDAS
parentheses
exponents
multiplication
division
addition
subtraction
there are no parentheses and no exponents so we want to do multiplication first
9*2= 18
so now your equation is 18 + 36 divided by 18
the next step is division so we want to divide 36 by 18
36/18= 2
now our final step is addition
18+2=20
the final answer is 20
it is 2(x-4)+3x=22 2(6-4)+3(6)