(-4 - 3)(1 - (3 + 5)) × 5
(-7)(-1 - 2) × 5
(-7)(-3) × 5
21 × 5
105
Answer:
The top one I'm pretty sure.
30 + 70 + D = 180
100 + D = 180
D = 80°
2x+5<14 .................................
<em>x</em> kg of Maxwell House coffee contains 0.13<em>x</em> kg of Columbian beans.
<em>y</em> kg of Folgers contains 0.21<em>y</em> kg of beans.
You want a mixture weighing 70 kg, so
<em>x</em> + <em>y</em> = 70
You also want this blend to consist of 19% Columbian beans, or 0.19 (70 kg) = 13.3 kg, so
0.13<em>x</em> + 0.21<em>y</em> = 13.3
Solve for <em>x</em> and <em>y</em> :
<em>x</em> + <em>y</em> = 70 ===> <em>y</em> = 70 - <em>x</em>
0.13<em>x</em> + 0.21<em>y</em> = 13.3 ===> 0.13<em>x</em> + 0.21 (70 - <em>x</em>) = 13.3
0.13<em>x</em> + 14.7 - 0.21<em>x</em> = 13.3
14.7 - 13.3 = 0.21<em>x</em> - 0.13<em>x</em>
1.4 = 0.08<em>x</em>
<em>x</em> = 17.5
<em>y</em> = 52.5
