for the system of equations
the three matrices needed to use Cramer's Rule are:
.
To use Cramer's Rule we have to calculate the three determinants listed below of the matrices listed below.
.
The value of the determinants are shown below.

The value of y is
.
Answer:
a= 22.5
b= 37.5
Step-by-step explanation:
<u>In</u><u> </u><u>△</u><u>BCD</u><u>:</u>
Applying Pythagoras' Theorem,
a² +30²= b²
a² +900= b² -----(1)
<u>In</u><u> </u><u>△</u><u>ABC</u><u>:</u>
Applying Pythagoras' Theorem,
b² +50²= (40 +a)² -----(2)
Substitute (1) into (2):
a² +900 +50²= 40² +2(40)(a) +a²<em> </em><em> </em><em> </em><em> </em><em> </em><em>(</em><em>expand</em><em> </em><em>bracket</em><em>)</em>
a² +900 +2500= 1600 +80a +a²
a² +3400= a² +80a +1600 <em>(</em><em>simplify</em><em>)</em>
a² +3400 -a² -80a -1600= 0 <em>(</em><em>bring</em><em> </em><em>everything</em><em> </em><em>to</em><em> </em><em>1</em><em> </em><em>side</em><em>)</em>
-80a +1800= 0
80a= 1800 <em>(</em><em>+</em><em>8</em><em>0</em><em> </em><em>on</em><em> </em><em>both</em><em> </em><em>sides</em><em>)</em>
a= 1800 ÷80
a= 22.5
Subst. a= 22.5 into (1):
22.5² +900= b²
b²= 506.25 +900
b²= 1406.25
b= √1406.25 <em>(</em><em>square</em><em> </em><em>root</em><em> </em><em>both</em><em> </em><em>sides</em><em>)</em>
b= 37.5 <em>(</em><em>reject</em><em> </em><em>negative</em><em> </em><em>value</em><em> </em><em>since</em><em> </em><em>b</em><em> </em><em>is</em><em> </em><em>a</em><em> </em><em>length</em><em>)</em>
☆(a +b)²= a² +2ab +b²
Answer:
The square root of 2, or the (1/2)th power of 2, written in mathematics as √2 or 21⁄2, is the positive algebraic number that, when multiplied by itself, equals the number 2. Technically, it is called the principal square root of 2, to distinguish it from the negative number with the same property
Step-by-step explanation:
You could make a small (easily repaired) leak and watch it for the amount of time you need to conclude what you need to.
Answer:
B
Step-by-step explanation:
$30 is your startup fee. You automatically pay that to join. When is is also $4 per month, you pay that much times however many months there are.