Help please, don’t understand

Step-by-step explanation:

look at the drawing as two HALF circles and substract the larger half circle from the smaller half circle or the difference between two circles divided by two

A = π r² for a WHOLE circle     A / 2 is the area for a HALF circle

Area of the rainbow is     Large Circle Area / 2  - Small Circle Area / 2

=  (π r²/2 large - π r²/2 small)

=  (π r² large - π r² small) / 2

=  π( r² large -  r² small) / 2

= π ((18cm)² - (12cm)²) / 2

= π(324 -144)cm² / 2

= 282.74   <  FINAL ANSWER

if you need just tell me and i will come to the rescue.

step-by-step explanation:

let x and 400 - x be the two numbers.  

==> 0.80x + 0.85(400 - x) = 400 - 68 from the statement of the problem.  

< ==> 0.80x + 0.85(400 - x) = 400 - 68  

==> 340 - 0.05x = 332  

< ==> -0.05x = -8 ==> x = 160, the first number ==> 400 - x = 240, the second number.