Why might you use the commutative property to multiply (-4) × 5?

Mathematics

1 answer:

grigory [225]3 years ago

7 0

Answer:

answer will be same -20

Step-by-step explanation:

because (-4)×5 is same as 5×(-4)

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The nine chips shown below are placed in a bag and then mixed up. Madeline draws one chip from this bag. What is the probability

babunello [35]

Complete question :

Image relating to the question can be found in the attachment below :

Answer:

4/9

Step-by-step explanation:

From the picture :

The nine chips are : 1, 2, 3, 4, 5, 6, 7, 8, 9

Even chips = 2, 4, 6, 8

Probability = number of required outcomes / (number of total possible outcomes)

Probability of drawing a chip with an even number :

P(even number) = number of even chips / total number of chips

P(even number) = 4 / 9

5 0

3 years ago

Find all values of c such that c/(c - 5) = 4/(c - 4). If you find more than one solution, then list the solutions you find separ

Deffense [45]

Answer:

$\large\boxed{\bold{NO\ REAL\ SOLUTIONS}}\\\boxed{x=4-2i,\ x=4+2i}$

Step-by-step explanation:

$Domain:\\c-4\neq0\ \wedge\ c-5\neq0\Rightarrow c\neq4\ \wedge\ c\neq5\\\\\dfrac{c}{c-5}=\dfrac{4}{c-4}\qquad\text{cross multiply}\\\\c(c-4)=4(c-5)\qquad\text{use the distributive property}\\\\c^2-4c=4c-20\qquad\text{subtract}\ 4c\ \text{from both sides}\\\\c^2-8c=-20\qquad\text{add 20 to both sides}\\\\c^2-8c+20=0\qquad\text{use the quadratic formula}$

$\text{for}\ ax^2+bx+c=0\\\\\text{if}\ b^2-4ac0,\ \text{then the equation has two solutions}\ x=\dfrac{-b\pm\sqrt{b^2-4ac}}{2a}$

$x^2-8x+20=0\\\\a=1,\ b=-8,\ c=20\\\\b^2-4ac=(-8)^2-4(1)(20)=64-80=-16$

$\text{In the set of complex numbers:}\\\\i=\sqrt{-1}\\\\\text{therefore}\ \sqrt{b^2-4ac}=\sqrt{-16}=\sqrt{(16)(-1)}=\sqrt{16}\cdot\sqrt{-1}=4i\\\\x=\dfrac{-(-8)\pm4i}{2(1)}=\dfrac{8\pm4i}{2}=\dfrac{8}{2}\pm\dfrac{4i}{2}=4\pm2i$