I don't know what the "six-step method" is supposed to be, so I'll just demonstrate the typical method for this problem.
Let <em>x</em> be the amount (in gal) of the 50% antifreeze solution that is required. The new solution will then have a total volume of (<em>x</em> + 60) gal.
Each gal of the 50% solution used contributes 0.5 gal of antifreeze. Similarly, each gal of the 30% solution contributes 0.3 gal of antifreeze. So the new solution will contain (0.5 <em>x</em> + 0.3 * 60) gal = (0.5 <em>x</em> + 18) gal of antifreeze.
We want the concentration of antifreeze to be 40% in the new solution, so we need to have
(0.5 <em>x</em> + 18) / (<em>x</em> + 60) = 0.4
Solve for <em>x</em> :
0.5 <em>x</em> + 18 = 0.4 (<em>x</em> + 60)
0.5 <em>x</em> + 18 = 0.4 <em>x</em> + 24
0.5 <em>x</em> - 0.4 <em>x</em> = 24 - 18
0.1 <em>x</em> = 6
<em>x</em> = 6/0.1 = 60 gal
18 1/2 -17 3/4
= 18.50 -17.75
= 0.75
= 3/4
The 4th selection is appropriate.
20+35+30= 1 hr&25 min so she should leave at 5:20
As isosceles triangle has two congruent sides with a third side
<span>that is the base. </span>
<span>A base angle of an isosceles triangle is one of the angles formed by </span>
<span>the base and another side. Base angles are equal because of the </span>
<span>definition of an isosceles triangle. </span>
<span>A picture would probably help here: </span>
<span>A </span>
<span>. </span>
<span>/ \ ABC = ACB = 39 degrees </span>
<span>/ BAC = ??</span>
<span>._______________. </span>
<span>B C </span>
<span>base </span>
<span>ABC is the isosceles triangle. AB is congruent to AC. Angle ABC </span>
<span>is congruent to angle ACB. These are the base angles. </span>
<span>Triangle is a convex polygon with three segments joining three non-collinear points. Each of the three segments is called a side, and each of the three non-collinear points is called a vertex. </span>
<span>Triangles can be categorized by the number of congruent sides they have. For instance, a triangle with no congruent sides is a scalene triangle; a triangle with two congruent sides is an isosceles triangle; a triangle with three congruent sides is an equilateral triangle. </span>
<span>Triangles can also be categorized by their angles. For instance, a triangle with three acute interior angles is an acute triangle; a triangle with one obtuse interior angle is an obtuse triangle; a triangle with one right interior angle is a right triangle; a triangle with three congruent interior angles is an equiangular triangle. </span>
<span>One property of a triangle is that the sum of the measures of the three interior angles is always 180 degrees (or pi radians). In addition, the exterior angle of a triangle is the supplement of the adjacent interior angle. The measure of the exterior angle is also the sum of the measures of the two remote interior angles.</span>
