There is a special kind of substitution which some books call it by comparison.
When the two equations are both
y=some function of x
y=some other function of x, then
we can substitute the second equation into the first giving
some function of x = some other function of x and start solving.
For example,
<span>y = –2x + 8
y = x – 1
substitute second into first
x-1=-2x+8
isolate x on left,
3x=9
x=3
second step is to substitute x=3 into second equation to get
y=x-1=3-1=2
Therefore the solution is (3,2)</span>
Unit price = price for one donut
if 12 donuts cost $8.50, then one donut would be:
$8.50/12 = 0.7083, or about $0.71
T=10.8, was the multiplication Symbol a part of the quest
V•w = (-7i +4j)•(-6i +5j) = (-7)×(-6) +4×5 = 42 +20
v•w = 62
The time taken for the element X to decay from 560 grams to 150 grams is 24.7 mins
<h3>How to determine the number of half-lives </h3>
- Original amount (N₀) = 560 g
- Amount remaining (N) = 150 g
- Number of half-lives (n) =?
2ⁿ = N₀ / N
2ⁿ = 560 / 150
2ⁿ = 3.73
Take the log of both side
Log 2ⁿ = Log 3.73
nLog 2 = Log 3.73
Divide both side by Log 2
n = Log 3.73 / Log 2
n = 1.9
<h3>How to determine the time </h3>
- Number of half-lives (n) = 1.9
- Half-life (t½) = 13 mins
t = n × t½
t = 1.9 × 13
t = 24.7 mins
Learn more about half life:
brainly.com/question/26374513
