Answer:
13mph
Step-by-step explanation:
you must multiply both fractions by the reciprocal of 1/65 which is 65/1
(1/5 * 65/1) / (1/65 * 65/1)
(65/5) / (65/65)
13/ 1
13/1 = 13
Answer:
Amount of vinegar. 100% : 20 milliliters
Amount of Italian dressing: 140 milliliters
Step-by-step explanation:
Let's call A the amount of vinegar. 100%
Let's call B the amount of Italian dressing . 12% vinegar
The resulting mixture should have 23% vinegar, and 160 milliliters.
Then we know that the total amount of mixture will be:
Then the total amount of pure antifreeze in the mixture will be:
Then we have two equations and two unknowns so we solve the system of equations. Multiply the first equation by -1 and add it to the second equation:
+
--------------------------------------
We substitute the value of B into one of the two equations and solve for A.
Answer:
<em>71.6 degrees </em>
Step-by-step explanation:
The formula for calculating the angle between two vectors is expressed as;
u.v = |u||v|cos theta
u.v = (8, 4).(9, -9)
u.v = 8(9)+4(-9)
u.v = 72-36
u.v = 36
|u| = √8²+4²
|u| = √64+16
|u| = √80
|v| = √9²+(-9)²
|v| = √81+81
|v| = √162
36 = √80*√162 cos theta
36 = √12960 cos theta
36 = 113.84 cos theta
cos theta = 36/113.84
cos theta = 36/113.84
cos theta = 0.3162
theta = arccos (0.3162)
<em>theta = 71.6 degrees </em>
<em>Hence the angle between the given vectors is 71.6 degrees </em>
Three main methods come to mind: Substitution method, Elimination method, Matrix row-reduction.The first two methods are taught in early grades in most high schools. Matrix row-reduction is taught in senior years in high school, or more likely, in the early years of a university math or science program.
