Answer: 
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This can be rewritten into 
The first blank is proportional because <span>two quantities is one in which the two quantities vary directly with one and other. </span>If<span> one item is doubled, the other, related item is also doubled. Because of this, it is also called a direct variation. </span>
To solve a system of linear equations graphically we graph both equations in the same coordinate system. The solution to the system will be in the point where the two lines intersect. The two lines intersect in (-3, -4) which is the solution to this system of equations
The first letter can be any one of 26 letters. For each one . . .
The second letter can be any one of 26 letters. For each one . . .
The first digit can be any one of 10 digits. For each one . . .
The second digit can be any one of 10 digits. For each one . . .
The third digit can be any one of 10 digits. For each one . . .
The fourth digit can be any one of 10 digits. For each one . . .
The fifth digit can be any one of 10 digits.
The total number of possibilities is
(26 x 26 x 10 x 10 x 10 x 10 x 10) =
( 26² x 10⁵) = (676 x 100,000) = <em>67,600,000</em> .