Joanna bought 7 notebooks and 14 pencils
Step-by-step explanation:
Step 1 :
Let x denote the number of notebooks and y denote the number of pencils Joanna bought.
Cost of one notebook = $ 2.30
Cost of one pencil = $1.42
Step 2 :
Total of notebooks and pencils bought = 21
=> x + y = 21 => y = 21-x
Total cost of notebooks and pencils = $35.98
=> 2.3x + 1.42y = 35.98
Substituting y = 21- x here , we have,
2.3x + 1.42 ( 21-x) = 35.98
2.3x + 29.82 - 1.42x = 35.98
0.88 x = 6.16
=> x = 7
y = 21-x = 21-7 = 14
Step 3 :
Answer :
Joanna bought 7 notebooks and 14 pencils
Answer:
domain: (–∞,∞) or all real numbers
range: (–∞,∞) or all real numbers
Step-by-step explanation:
domain is left to right (x-axis). looking at the graph, as you go from left to right, the x-values are infinitely getting more negative and positive.
range is bottom to top (y-axis). as you go from bottom to top, the y-values are infinitely getting more negative and positive.
Answer:
2329 are girls out of 37 boys in school in 2366 total
Answer:
90 g of water should be added and he will make 900 g of solution.
Step-by-step explanation:
Let x g be the amount of salt Ilya add to 810g of water to make 10% solution. Then 810+x g is the amount of new solution. Thus,
810+x - 100%,
x - 10%.
Mathematically,
So 90 g of water should be added and he will make 810+90=900 g of solution.
For example, the additive inverse of 12 is –12. The additive inverse of –3 is 3. Formally, the additive inverse of x is –x. Note: The sum of a number and its additive inverse is 0.
